Cyano on Sandbed

[msderganc]

So I've been having an issue with cyano only on my sandbed only since June. I originally thought it was just the normal progression, but it has not gotten better. I don't see any other algae really at all, and I only clean my glass every ~5 days. I have no idea what to do, other than replace my sandbed at this point.

For some background on my tank, it's a 190g display, roughly 260g system. It's been up since November of last year. I'm currently using an ATI Powermodule 8x54w + 3x75w LED. The bulbs are about a month old (5xB+, 2xP+, and 1 C+). For filtration, I have a ~20g refugium with chaeto and live rock. I'm also running All-in-one biopellets, and ROX GAC in reactors, with Purigen passively in the sump. My skimmer is a SRO XP3000int. I'm running two Tunze 6105s and two MP40s for flow, in addition to about 1200gph through the sump.

In the tank, it's 90%+ SPS, with a few acans, zoas and palys. I have two small tangs, two schooling bannerfish, two watanabei angels, a foxface, and about 12 other smaller fish. I currently feed four cubes of homemade food per day (two in the morning, two in the evening), plus a small amount of Neptune Crossover Diet pellets twice a day in the middle. 3-4 times a week, I'll give them about a 3"x3" sheet of nori.

As for parameters, I've had some alkalinity swings recently, but I should be over them. I have a kalk reactor supplemented by dosers for calcium and alkalinity.
NO3 - .2 (Salifert)
PO4 - 0 (both by Hanna Phosphate and Phosphorus)
Alk - 7.5 (7.2-7.7)
Calc - 400
Mag - 1300
Salinity - 34ppt (slowly shifting up to 35ppt)

Here's what I've done so far:
1. Reduced feeding - seemed to have a negative effect, actually. I think it may have been due to less nitrate which stopped the bacteria from processing the phosphate.
2. Removed about half of the sand, going from a 1.5inch sandbed to about 0.75 inch - no change
3. Increased flow. I moved the MP40s to where they were pushing sand, essentially. This helped in some spots, but it more slowed the cyano than eliminated it.
4. 3 days lights out, 1 day actinics. Eliminated the cyano while the lights were out, then it came back like nothing had happened.
5. Vacuumed / stirred sandbed - seemed to get a lot of detritus up, but didn't effect the cyano. If I stir the sandbed up in the morning, it will stay clear until the next day.
6. Dosed bacteria / zeozym. I've tried every one of the products out there with no effect - zeozym, zeobac, coral snow, microbacter 7, prodibio, you name it.
7. GFO. I've been running various types of GFO, changing it as often as every couple of days thinking that it may be phosphates.
8. Biopellets. I've adjusted my effluent a number of times with no result. I've gone everywhere from a trickle to ~500gph. I've tried a few different types of biopellets as well.
9. Liquid carbon dosing. I have tried using NO3PO4X to reduce the nutrient levels while the biopellets were seeding. Extremely low nutrients, but little to no effect on the cyano.
10. Chemiclean. Finally, after all of that, I tried chemiclean. It worked well on the tiny amount of cyano on the rocks, but the sandbed was more or less unaffected. Maybe a slight recession, but not much. Twice now I've tried with no luck.

I know people are going to say it's a nutrient issue, but I'm not sure how that's possible. My phosphates are never over .05, and almost always read 0, even when the cyano has been removed. I don't have any nuisance algae growth except a relatively light covering of cyano on the sandbed (it's not smothering anything, looks more like reddish brown dusting on the sand). I'm pretty sure it's not dinos, since it doesn't bubble or go away at night.

I'm down to three possible solutions:
1. Replace the sandbed. Any suggestions? I was thinking Reef Flakes.
2. Try another chemical solution. Any suggestions?
3. Try removing the biopellets and just carbon dosing.

Any other recommendations? I'm open to anything at this point.

[msderganc]

No suggestions?

[adambom]

You could try slowly raising alkalinity. Cyano prefers to grow in low alkalinity conditions.

Have you tested for iron? High iron levels could be contributing as well. I should also ask, what sort of CUC do you have?

[robert s b.]

How long have you been running the AIO Biopellets?

[msderganc]

You could try slowly raising alkalinity. Cyano prefers to grow in low alkalinity conditions.

Have you tested for iron? High iron levels could be contributing as well. I should also ask, what sort of CUC do you have?

Thanks, I'd been keeping them lower as I have burnt some SPS tips since it's a low nutrient environment. Anywhere over ~8.5 and my SPS suffer.

I hadn't tested iron recently, I'll have to do that. I did test a couple of months ago and it was on the low side.

[msderganc]

How long have you been running the AIO Biopellets?

Since they came out, so a few months now. I think I received them in late June.

I had the cyano before the AIOs (on different biopellets), and I thought the cyano was receding a month ago. But then it just came back with a vengeance recently out of the blue.

It's strange because I have 0 cyano on the rocks, it's all dusting the sand.

[B.BASH]

I'm having the same problem i think it may be related to spectrum just a shot in the dark

[robert s b.]

I just started using the AIO biopellet about 3 weeks ago, and developed a little cyano on the sandbed and some on the rocks. Before the AIO usage, I didn't have the problem.

[SammyL]

Thanks, I'd been keeping them lower as I have burnt some SPS tips since it's a low nutrient environment. Anywhere over ~8.5 and my SPS suffer.

I hadn't tested iron recently, I'll have to do that. I did test a couple of months ago and it was on the low side.

I know that I am new to this but how do you feel that you have a "low Nutrient environment"? With that bio load and your feeding schedule, I would think that is a high nutrient environment, what am I missing?

Sorry to be a pain, just trying to learn more.

[msderganc]

I know that I am new to this but how do you feel that you have a "low Nutrient environment"? With that bio load and your feeding schedule, I would think that is a high nutrient environment, what am I missing?

Sorry to be a pain, just trying to learn more.

The amount of nutrients has more to do with filtration than the actual stocking level. Since my nitrates and phosphates are generally undetectable (or very close to it), I referred to it as low nutrient. I think I've been on the border of ultra low nutrient (ULN), which is why the cyano has perplexed me. The effects of higher than natural alkalinity in low nutrient systems is well documented, which is why, for instance, Zeovit recommends staying around 7-8 dkH with their system as well.

My only guess as to how I'm still getting cyano is through excessive carbon dosing. I think the cyano might be metabolizing the carbon, even though phosphate and nitrate are essentially 0.

[msderganc]

I just started using the AIO biopellet about 3 weeks ago, and developed a little cyano on the sandbed and some on the rocks. Before the AIO usage, I didn't have the problem.

I think this is pretty normal from everything I've read. I think I might have been overdosing bacteria and carbon. I've decided on the following:

1. Cut out all light for three days
2. Simultaneously dose Chemi-clean
3. Remove biopellets and cease any carbon dosing (I had been using a small about of NO3PO4X to help while the biopellets came up to speed.
4. Stop all bacteria dosing.

I'm just going to run some GFO and let my refugium pick up the rest. My nutrients may come up a little, but it should help the system stabilize.

[msderganc]

I'm having the same problem i think it may be related to spectrum just a shot in the dark

Thanks, I thought it was this as well, and changed my spectrum to be bluer. No luck in my system, though.

[bluecoyote79]

3 days lights out while dosing chemi-clean worked for me. I also stopped stirring the sandbed as much as I had been, dunno if that helped or not though.

[immortl]

You mentioned it started in June. How much natural sunlight hits the tank during the day? I notice an increase in cyano during summer months when more natural light (none really direct, light drapes always drawn) enters the room. Days are getting shorter now, so less sunlight, but I did have issues even last winter.

I have no idea why my cyano all of a sudden went away but it did over the past 3 weeks. I'm feeding the same, tank is coming up on 3 years old. What was weird is that I was way overdue for a water change. Hadn't done one in nearly three months and suddenly the cyano went away. I just did a water change this past weekend and so far, it's staying away.

[msderganc]

You mentioned it started in June. How much natural sunlight hits the tank during the day? I notice an increase in cyano during summer months when more natural light (none really direct, light drapes always drawn) enters the room. Days are getting shorter now, so less sunlight, but I did have issues even last winter.

I have no idea why my cyano all of a sudden went away but it did over the past 3 weeks. I'm feeding the same, tank is coming up on 3 years old. What was weird is that I was way overdue for a water change. Hadn't done one in nearly three months and suddenly the cyano went away. I just did a water change this past weekend and so far, it's staying away.

Yeah, I've considered this as well. The research I've done says that cyano prefers higher temperatures. My tank stays between 76-77 in the Winter and about 78-80 in the Summer. It gets almost no sunlight (no direct sunlight at all). I haven't seen any correlation myself between temperature and cyano, though. Recently the tank has started to cool down for the fall, and the cyano has gotten worse.

The water change gave me an interesting thought - salt choice. I've used Red Sea Coral Pro for the last few years, and I've noticed the cyano outbreak only on the last container (more or less since June).

Recently, I bought a bunch of IO (Randy Holmes-Farley mentioned he uses it because it has 0 organics in it) to switch. I've been alternating over the past month, but after my last chemi-clean treatment, I changed ~60 gallons with RSCP. The next day was the worst the cyano has been in a while.

I've read some other people have had cyano with a bad batch of salt (and RSCP in specific), so I think I'll use IO for the the whole water change at the end of this treatment and see what that does.

[PL-Reef]

Yeah, I've considered this as well. The research I've done says that cyano prefers higher temperatures. My tank stays between 76-77 in the Winter and about 78-80 in the Summer. It gets almost no sunlight (no direct sunlight at all). I haven't seen any correlation myself between temperature and cyano, though. Recently the tank has started to cool down for the fall, and the cyano has gotten worse.

The water change gave me an interesting thought - salt choice. I've used Red Sea Coral Pro for the last few years, and I've noticed the cyano outbreak only on the last container (more or less since June).

Recently, I bought a bunch of IO (Randy Holmes-Farley mentioned he uses it because it has 0 organics in it) to switch. I've been alternating over the past month, but after my last chemi-clean treatment, I changed ~60 gallons with RSCP. The next day was the worst the cyano has been in a while.

I've read some other people have had cyano with a bad batch of salt (and RSCP in specific), so I think I'll use IO for the the whole water change at the end of this treatment and see what that does.

Very interesting. I bought a new bag of regular Red Sea salt and recently noticed that I have some cyano starting in my sand bed and on some rock. I been doing 30g water changes weekly in hopes of clearing it up. I never thought about the possibility that it might be coming from the salt itself. Maybe for my next WC I'll try some other brand ( maybe IO) and see what happens. I'll return to this thread and give you guys some feed back.

[Rot26]

I had cyano going about 3 months ago and it was slowly, but steadily, getting worse. I added more water movement to try to get rid of dead spots, but that just shifted the cyano to different areas. I have been trying to feed less, but the thing that got rid of it was added an algae scrubber. After having that for 3 full weeks now, I have no cyano visible.

[msderganc]

I had cyano going about 3 months ago and it was slowly, but steadily, getting worse. I added more water movement to try to get rid of dead spots, but that just shifted the cyano to different areas. I have been trying to feed less, but the thing that got rid of it was added an algae scrubber. After having that for 3 full weeks now, I have no cyano visible.

Out of desperation I looked into an algae scrubber. If all of this doesn't work, I'm considering abandoning biopellets and going to a scrubber or maybe even full Zeovit.

[msderganc]

Very interesting. I bought a new bag of regular Red Sea salt and recently noticed that I have some cyano starting in my sand bed and on some rock. I been doing 30g water changes weekly in hopes of clearing it up. I never thought about the possibility that it might be coming from the salt itself. Maybe for my next WC I'll try some other brand ( maybe IO) and see what happens. I'll return to this thread and give you guys some feed back.

Thanks, keep us posted!

[PL-Reef]

Will do. I've had 30g of mixed saltwater (using RedSea) in my fish room for the past 4 days. I hate to waste it. After tonight's WC I'll switch to IO for a few WCs and see what happens.

[SammyL]

The amount of nutrients has more to do with filtration than the actual stocking level. Since my nitrates and phosphates are generally undetectable (or very close to it), I referred to it as low nutrient. I think I've been on the border of ultra low nutrient (ULN), which is why the cyano has perplexed me. The effects of higher than natural alkalinity in low nutrient systems is well documented, which is why, for instance, Zeovit recommends staying around 7-8 dkH with their system as well.

My only guess as to how I'm still getting cyano is through excessive carbon dosing. I think the cyano might be metabolizing the carbon, even though phosphate and nitrate are essentially 0.

Thank you for explaining....

[B.BASH]

I don't think we can actually rid our systems of cyano just control it

[Dan_P]

For some background on my tank, it's a 190g display, roughly 260g system. It's been up since November of last year. I'm currently using an ATI Powermodule 8x54w + 3x75w LED. The bulbs are about a month old (5xB+, 2xP+, and 1 C+). For filtration, I have a ~20g refugium with chaeto and live rock. I'm also running All-in-one biopellets, and ROX GAC in reactors, with Purigen passively in the sump. My skimmer is a SRO XP3000int. I'm running two Tunze 6105s and two MP40s for flow, in addition to about 1200gph through the sump.

In the tank, it's 90%+ SPS, with a few acans, zoas and palys. I have two small tangs, two schooling bannerfish, two watanabei angels, a foxface, and about 12 other smaller fish. I currently feed four cubes of homemade food per day (two in the morning, two in the evening), plus a small amount of Neptune Crossover Diet pellets twice a day in the middle. 3-4 times a week, I'll give them about a 3"x3" sheet of nori.

As for parameters, I've had some alkalinity swings recently, but I should be over them. I have a kalk reactor supplemented by dosers for calcium and alkalinity.
NO3 - .2 (Salifert)
PO4 - 0 (both by Hanna Phosphate and Phosphorus)
Alk - 7.5 (7.2-7.7)
Calc - 400
Mag - 1300
Salinity - 34ppt (slowly shifting up to 35ppt)

Here's what I've done so far:
1. Reduced feeding - seemed to have a negative effect, actually. I think it may have been due to less nitrate which stopped the bacteria from processing the phosphate.
2. Removed about half of the sand, going from a 1.5inch sandbed to about 0.75 inch - no change
3. Increased flow. I moved the MP40s to where they were pushing sand, essentially. This helped in some spots, but it more slowed the cyano than eliminated it.
4. 3 days lights out, 1 day actinics. Eliminated the cyano while the lights were out, then it came back like nothing had happened.
5. Vacuumed / stirred sandbed - seemed to get a lot of detritus up, but didn't effect the cyano. If I stir the sandbed up in the morning, it will stay clear until the next day.
6. Dosed bacteria / zeozym. I've tried every one of the products out there with no effect - zeozym, zeobac, coral snow, microbacter 7, prodibio, you name it.
7. GFO. I've been running various types of GFO, changing it as often as every couple of days thinking that it may be phosphates.
8. Biopellets. I've adjusted my effluent a number of times with no result. I've gone everywhere from a trickle to ~500gph. I've tried a few different types of biopellets as well.
9. Liquid carbon dosing. I have tried using NO3PO4X to reduce the nutrient levels while the biopellets were seeding. Extremely low nutrients, but little to no effect on the cyano.
10. Chemiclean. Finally, after all of that, I tried chemiclean. It worked well on the tiny amount of cyano on the rocks, but the sandbed was more or less unaffected. Maybe a slight recession, but not much. Twice now I've tried with no luck.

I know people are going to say it's a nutrient issue, but I'm not sure how that's possible. My phosphates are never over .05, and almost always read 0, even when the cyano has been removed. I don't have any nuisance algae growth except a relatively light covering of cyano on the sandbed (it's not smothering anything, looks more like reddish brown dusting on the sand). I'm pretty sure it's not dinos, since it doesn't bubble or go away at night.

I'm down to three possible solutions:
1. Replace the sandbed. Any suggestions? I was thinking Reef Flakes.
2. Try another chemical solution. Any suggestions?
3. Try removing the biopellets and just carbon dosing.

Any other recommendations? I'm open to anything at this point.

The aquarium is still maturing so a persistent cyanobacteria mat is not unusual and the cause is not likely to be one factor. Most aquarist try multiple remedies to get rid of the red slime, so, we typically learn little from these uncontrolled experiments. It is likely that if you did nothing the mats would eventually subside. What you have done so far is exactly the same things suggested in the last ten years of red slime posts on Reef Central.

Since the advent of dosing carbon and biopellets, there has been posts about cyanobacteria blooms, seemingly associated with the use of these methods. So, you might consider this as a source of nutrient for your cyanobacteria.

The three day lights out method probably does not kill cyanobacteria as much as disrupts the large mats which seem to be like self-sustaining ecosystems. So, it would not be unusual for the red mats to reform.

I have read a small number of posts where established systems develop cyanobacteria outbreaks when the system is physically is disrupted, e.g., removing or vacuuming the substrate. Based on this limited data and if you have the patience, try leaving the substrate alone as much as possible and only vacuum up the mats. I think what is happening is that every time you disturb the sand, you are weakening the other microbial communities that compete with cyanobacteria.

You might consider doing nothing more than cosmetic work from this point onwards, a gently vacuuming up of the mats from the sand. The tank will look better and this will help you wait this out. Take photographs every few days of the cyano mats so you can more accurately gauge progress. Things will change slowly for the better but you will miss this if you don't have a photographic record and then you will be tempted to start trying another remedy or changing something.

[msderganc]

The aquarium is still maturing so a persistent cyanobacteria mat is not unusual and the cause is not likely to be one factor. Most aquarist try multiple remedies to get rid of the red slime, so, we typically learn little from these uncontrolled experiments. It is likely that if you did nothing the mats would eventually subside. What you have done so far is exactly the same things suggested in the last ten years of red slime posts on Reef Central.

Since the advent of dosing carbon and biopellets, there has been posts about cyanobacteria blooms, seemingly associated with the use of these methods. So, you might consider this as a source of nutrient for your cyanobacteria.

The three day lights out method probably does not kill cyanobacteria as much as disrupts the large mats which seem to be like self-sustaining ecosystems. So, it would not be unusual for the red mats to reform.

I have read a small number of posts where established systems develop cyanobacteria outbreaks when the system is physically is disrupted, e.g., removing or vacuuming the substrate. Based on this limited data and if you have the patience, try leaving the substrate alone as much as possible and only vacuum up the mats. I think what is happening is that every time you disturb the sand, you are weakening the other microbial communities that compete with cyanobacteria.

You might consider doing nothing more than cosmetic work from this point onwards, a gently vacuuming up of the mats from the sand. The tank will look better and this will help you wait this out. Take photographs every few days of the cyano mats so you can more accurately gauge progress. Things will change slowly for the better but you will miss this if you don't have a photographic record and then you will be tempted to start trying another remedy or changing something.

Thanks for the very thoughtful post. After I get through this chemiclean dose, I'll try that with reduced carbon dosing.

[msderganc]

So I finished the round of chemi-clean and have one more day on the lights out. I lost one coral, a small red dragon frag, probably due to the alkalinity swing. For anyone else who does a lights out, monitor your alkalinity closely. I saw a pretty drastic swing on the second day since I'm guessing the corals weren't using as much (went from about 7.3 to 8.6 dkH in 12 hours). I took my biopellets offline, and my phosphates and nitrates have risen to 0.10 and 2.5 ppm respectively. I've also burned through probably 4-5 cups of GFO in three days, so I'm guessing something is leeching phosphate (measuring the effluent from the reactor - I replaced the media when the effluent was equivalent to the DT readings). Maybe the sand is releasing phosphate? It perplexes me, because the sand is less than a year old, but who knows?

I ended up putting the biopellets back online today, but have cut out any other carbon dosing or bacterial additions. I've also reduced the turnover in the reactor to ~90 gph. it keeps about half of the pellets moving at any given time. Tomorrow I'll be bringing the lights back on with a reduced photoperiod and little to no white light.

One other thing I wanted to add to this - I have not seen ANY cyano in my refugium (at all, since this whole thing started). It has about an inch and a half of miracle mud, 20 lbs of live rock, and a grapefruit sized ball of chaeto in it. The flow rate is relatively slow, maybe 300-400 gph. This would support my hypothesis that the sand is leaching phosphate, I think.

[msderganc]

delete.

[B.BASH]

Your rise in phosphate could be due to algae die off algae releases it when it dies I'm not sure if cyano feeds on phosphate but if it does it will probably release it also

[msderganc]

Your rise in phosphate could be due to algae die off algae releases it when it dies I'm not sure if cyano feeds on phosphate but if it does it will probably release it also

True. It's down to about 0.04 right now, so maybe it was just the cyanobacteria die off (fingers crossed).

Also - I ended up ordering the Reef Dynamics recirculating biopellet reactor. It should be here in a couple weeks, so I'll write a review when I get it. Really excited about being able to control effluent separately from keeping the pellets suspended.

[msderganc]

So, after two consecutive two day treatments of Chemiclean, about six cups of HC GFO, three days of lights out, and a day of actinic only, a little cyano came back on the sandbed.

My phosphates are 0 (by both the Hanna Phosphate and Phosphorous tests, before any cyano showed up), and my nitrates are about 2.5ppm.

I'm going to just wait it out this time, and hope that this is just part of a mini-cycle from stirring the sandbed.

[msderganc]

In varying amounts since June.

[B.BASH]

Still there? Suck it out. Without disturbing sand bed I use a small diameter tube 3/8 or so and siphon it out into a filter sock then return the water to dt

[msderganc]

Still there? Suck it out. Without disturbing sand bed I use a small diameter tube 3/8 or so and siphon it out into a filter sock then return the water to dt

Yeah, it is just a very little bit. I'm planning on just leaving it for a week or so, and then I think I'll try siphoning like that. Thanks for the suggestion!

[msderganc]

Just a small update - the cyano is growing a little but it's significantly slower. I'm going to continue to wait it out. I've kept the biopellets on a slow tumble (can't wait until I get my ReefDynamics reactor so I can really tune it), and the GFO online. My phosphates are at 0, and my nitrates are about 2.5ppm (and rising around .5 ppm per day). I'm wondering if the imbalance there is helping the cyano, but I doubt it.

Also - most of my corals were very happy after the lights out. I saw tons of growth after that period, so I've cut back my photoperiod in general to gauge the effect. I did lose one Red Dragon frag, but that was probably more a function of the alkalinity swing than the lights out or chemi-clean.

[Bryopsis]

I will say this about my experience with biopellets so far.

They're awesome! (no really, it completely baffles me how easy it is to take care of nitrates and phosphates)

Now, onto the realities.

I was using a TLF 150 with pellets and a half-a$$ attempt at a recirculating mod. This did ok, but I was having cyano over everything. (I think my recirculating was a bit off as compared to the system you see with the legitimate reactors)

The biggest thing I think that made an improvement, slowing the tumble down so only half the pellets move. I did get an Aqualund reactor (like the reef dynamics) and I can tell that the exposure to air (yet again) just absolutely destroys the bacteria. My nitrates and phosphates have been elevated again slightly, and guess what, some cyano pops up. Not at all like it was, but I do believe that some of the carbon and/or bacteria is escaping the reactor and planting itself around the tank.

Recently it also occurred to me, why pull water from the tank for the input to the reactor?
So I've made a switch.

Before, when I would open the reactor, clean it, etc, cyano bloom. (it seemed lessened when I slowed flow to keep more bacteria in the reactor, but still present. I think the bloom is also related to the lack of filtration if the bacterial mass gets wiped out)

Otherwise, that was always with reactor output to skimmer input, and reactor input in tank.

The other day I realized, "well, if bacteria and/or carbon is indeed escaping, and feeding cyano (which is entirely plausible) why pull the water from the tank?"

So I've changed it to this.
reactor output to skimmer input, skimmer output to reactor input.(it's not 100%, I lay the reactor input in the chamber of the skimmer output;it's the LX2000s hob)

Basically, a double recirculating setup in a nutshell. But with the hopes of allow any bacteria that isn't skimmed out, to be sucked back into the reactor where it can be "utilized" once again.

Since I've done this, the cyano bloom is still there, but no where near as "bang my head against a wall" type of problem. (But I also just switched to the new reactor)

It's something like this that makes me want to dose vinegar because I have seen many people say it helps, but I've also seen many people say it doesn't matter. All in all, I don't want to drive my ph down, let alone abandon the obvious progress I've seen with biopellets. (and even better progress that I've seen in the last few weeks changing the reactor input placed in the skimmer output) Also another thought with that is oxygen levels available, and I guarantee the levels are higher straight from the skimmer than in the tank.

Just a thought...

[msderganc]

I will say this about my experience with biopellets so far.

They're awesome! (no really, it completely baffles me how easy it is to take care of nitrates and phosphates)

Now, onto the realities.

I was using a TLF 150 with pellets and a half-a$$ attempt at a recirculating mod. This did ok, but I was having cyano over everything. (I think my recirculating was a bit off as compared to the system you see with the legitimate reactors)

The biggest thing I think that made an improvement, slowing the tumble down so only half the pellets move. I did get an Aqualund reactor (like the reef dynamics) and I can tell that the exposure to air (yet again) just absolutely destroys the bacteria. My nitrates and phosphates have been elevated again slightly, and guess what, some cyano pops up. Not at all like it was, but I do believe that some of the carbon and/or bacteria is escaping the reactor and planting itself around the tank.

Recently it also occurred to me, why pull water from the tank for the input to the reactor?
So I've made a switch.

Before, when I would open the reactor, clean it, etc, cyano bloom. (it seemed lessened when I slowed flow to keep more bacteria in the reactor, but still present. I think the bloom is also related to the lack of filtration if the bacterial mass gets wiped out)

Otherwise, that was always with reactor output to skimmer input, and reactor input in tank.

The other day I realized, "well, if bacteria and/or carbon is indeed escaping, and feeding cyano (which is entirely plausible) why pull the water from the tank?"

So I've changed it to this.
reactor output to skimmer input, skimmer output to reactor input.(it's not 100%, I lay the reactor input in the chamber of the skimmer output;it's the LX2000s hob)

Basically, a double recirculating setup in a nutshell. But with the hopes of allow any bacteria that isn't skimmed out, to be sucked back into the reactor where it can be "utilized" once again.

Since I've done this, the cyano bloom is still there, but no where near as "bang my head against a wall" type of problem. (But I also just switched to the new reactor)

It's something like this that makes me want to dose vinegar because I have seen many people say it helps, but I've also seen many people say it doesn't matter. All in all, I don't want to drive my ph down, let alone abandon the obvious progress I've seen with biopellets. (and even better progress that I've seen in the last few weeks changing the reactor input placed in the skimmer output) Also another thought with that is oxygen levels available, and I guarantee the levels are higher straight from the skimmer than in the tank.

Just a thought...

Thanks! I'm definitely going to use that when I get the new reactor. My output goes right next to the input to the skimmer. My input is pretty close, but I will definitely plumb it in (I can do it pretty easily with my setup).

What size tank do you have? What biopellets are you using? How many?

[Oliver77]

I had the same type of problem on my 75 , bought a biopellet reactor I run 350 ml biopellets and I started using probido biodigest and the algae growth stopped receded all the algae on the sandbed dissipated. It shocked my corals , once I increased my bioload my sps perked back up

[Bryopsis]

Thanks! I'm definitely going to use that when I get the new reactor. My output goes right next to the input to the skimmer. My input is pretty close, but I will definitely plumb it in (I can do it pretty easily with my setup).

What size tank do you have? What biopellets are you using? How many?

75 gallon standard, using ecobak plus atm(used their first gen before with the tlf 150 hackjob)

I honestly think I'm using a bit less than what's suggested by everyone (1 cup per 50 is it?) I've cleaned the previous reactor a couple times, and now moved reactors, prolly lost quite a few because even with the reactor on full speed now, i'm seeing 2-5ppm nitrates.(could very well be too early to tune it) I wonder if this may have any affect on the cyano as well, but I've just left it alone so far so the bacterial population can regrow. Can't see much of a mass in the reactor on the pellets yet. (changed reactor maybe 3 weeks ago)

With the other comment, one of the better tanks I've seen using biopellets and minimal other things, the guy was using biodigest and bioptim. Was thinking about trying this myself and it seems the biodigest would help a lot because of random detritus. (dudes tank was spotless)

[msderganc]

75 gallon standard, using ecobak plus atm(used their first gen before with the tlf 150 hackjob)

I honestly think I'm using a bit less than what's suggested by everyone (1 cup per 50 is it?) I've cleaned the previous reactor a couple times, and now moved reactors, prolly lost quite a few because even with the reactor on full speed now, i'm seeing 2-5ppm nitrates.(could very well be too early to tune it) I wonder if this may have any affect on the cyano as well, but I've just left it alone so far so the bacterial population can regrow. Can't see much of a mass in the reactor on the pellets yet. (changed reactor maybe 3 weeks ago)

With the other comment, one of the better tanks I've seen using biopellets and minimal other things, the guy was using biodigest and bioptim. Was thinking about trying this myself and it seems the biodigest would help a lot because of random detritus. (dudes tank was spotless)

Yeah, I think the recommended amount varies based on the type of pellet. I asked the question because I've seen a huge variation in the amount per gallon that people are using, similar to carbon dosing in general.

I've also seen that nitrates take a while to come down sometimes with biopellets. Mine have been level for a week or so at that 2.5ppm level (by Salifert), but initially took a long time to drop (I've seen some reports that it took 5-6 months for the pellets to finally kick in after a major change). Finding that sweet spot of circulation, effluent flow, and amount of pellets is tough because of how delayed the outcomes are.

I've used the biodigest and biooptim for a couple of months. What I can say is that it didn't affect the cyano one way or the other from what I could tell. I did see a noticeable detritus reduction, and my rocks looked cleaner. I'm on the fence about continuing, but I'm using about a half dose (buy them separately if you can, it's cheaper than their combo package) and it's maintained the cleanliness.

[B.BASH]

I do believe there are several posts with a correlation between carbon dosing and or bio pellets and increased cyano growth

[philosophile]

In my experience, when I tried vodka dosing, I had huge blooms of cyano, even when I ramped slowly.... So if you were carbon dosing AND running biopellets (which is a form of carbon dosing) I would suspect that would be the cause.

Where is the effluent from the biopellets going? Most success stories with biopellets have the effluent going to a skimmer. You don't have direct all the effluent there, but if you can get the majority there that would help, I would imagine.

On that note, how often are you cleaning your skimmer? if it isn't pulling out all the bacteria, when the bacteria gets back into the display, it could die, and fuel more cyano.

[Bryopsis]

BBash, Philosophile, you're bout spot on :)

I think that's the major problem with carbon dosing, finding that sweet spot. :)

I totally agree though msderganc, I hate the delays in reactions. lol

[msderganc]

In my experience, when I tried vodka dosing, I had huge blooms of cyano, even when I ramped slowly.... So if you were carbon dosing AND running biopellets (which is a form of carbon dosing) I would suspect that would be the cause.

Where is the effluent from the biopellets going? Most success stories with biopellets have the effluent going to a skimmer. You don't have direct all the effluent there, but if you can get the majority there that would help, I would imagine.

On that note, how often are you cleaning your skimmer? if it isn't pulling out all the bacteria, when the bacteria gets back into the display, it could die, and fuel more cyano.
I definitely agree that I was overdoing the carbon dosing, primarily to keep the tank parameters in check as the biopellets got up to speed.

I've got a neck cleaner on the skimmer, and I'm doing a full clean out every ~2-3 months. My effluent output is about 2 inches from my skimmer input. I have had a hard time with the skimmer (SRO XP 3000INT) getting consistent skimmate, but I think I've finally gotten it pretty dialed in.

[msderganc]

Update - I've left the sandbed alone for a while, except in one area as a test. The areas with less disturbance have cleared up, but the area which I stirred still has cyano.

It's also in a slightly lower flow area, but I definitely think the stirring was disturbing the beneficial bacteria and allowing the cyano to take hold.

Also - my phosphate has continuously read 0 (no GFO online) with nitrates varying between 2-4ppm by the Salifert test.

[sonic]

Any updates?

I've been going through basically the same thing as you but I don't do any biopellets, GFO, carbon dosing etc. It all started happening a couple of weeks after I upgraded my tank using all new sand, except a cup or so to help seed it. That was 3 months ago. Also thinking its the sand leaching phosphates...

[msderganc]

Any updates?

I've been going through basically the same thing as you but I don't do any biopellets, GFO, carbon dosing etc. It all started happening a couple of weeks after I upgraded my tank using all new sand, except a cup or so to help seed it. That was 3 months ago. Also thinking its the sand leaching phosphates...

Completely clear of cyano. In the end, I just let it sit until it ate all the phosphates.

[sonic]

That's good to hear. Did you keep running GFO? How long did it take to go away?