Algae Scrubber Basics

[Spar]

any idea if an algae scrubber would impair mangrove growth?

[Staisman]

I decide to give ATS go in my system. I had little GHA along with Bryopsis.

This is initial setup, on one of my intake lines to the sump.




This is one week after, you can see some diatoms grow on it



And this is second week



I have been running this for 2 weeks so far and I can see the positive results already in my DT. Along with ATS i am running GFO and Skimmer.

[Spar]

just curious, what is the general consensus on if using a drain line or dedicated pump? I will have 6 drain lines on my new setup, so may as well use one of those, but curious if it is more or less reliable in comparison.

[hkgar]

I initially set mine up to the drainline from the DT to the sump. Because I only have 1 drain to the sump, I could not control the flow, except by controling the flow from the return pump, Iwaki 100.

I added another t to the manifold from the return line and can now control the flow with a gate valve. I have plenty of excess capacity with the Iwaki.

[SantaMonica]

Here you can see the dark band of brown algae against the back rock that I'm trying to get rid off.

You could of course scrape that off, but the scrubber should eventually remove it.

any idea if an algae scrubber would impair mangrove growth?

Theoretically the mangroves should grow less, but I don't know of any tests that have been done.

And this is second week

That's a pretty fast start.

what is the general consensus on if using a drain line or dedicated pump?

Not one really. Since both are DIY, it's more based on your DIY skills.

[karimwassef]

No feedback on using the excess MH light with the return flow pipe converted into a channel with a screen?

[codyreed29]

I just finished my chinesse led deep red ats first one I ever made from acrylic, 2 one foot heatsinks on both side and 10 leds at 3w with lpc 35 700 meanwell. It's really bright and it gives my growout tan a back drop lighting I kinda like.

Its on a 29 with 20L sump and will be my only filtration besides water changes for all my clownfish to grow in im hoping 14 x 5 inches will be enough to keep nitrates low with a lot of fish probably 40+ clownfish and 2 cubes of food a day.

Just got to get a few pvc pieces and shell be up and running.

[codyreed29]

Thanks for all the information and help.

[karimwassef]

Here's the stuff I'm trying remove. I think it's brown hair algae - very short tufts but very strong attachment to the rock.

[karimwassef]

Also, how do you keep the plastic clean so that the GHA grows on the screen, not the plastic screen?

[Floyd R Turbo]

Originally Posted by karimwassef

Here's the stuff I'm trying remove. I think it's brown hair algae - very short tufts but very strong attachment to the rock.

Probably a combination of blowing off the rocks occasionally and temporarily running a filter sock while doing so, plus the scrubber ( a relatively strong one, but not oversized necessarily) should get you on the path to getting that under control

Originally Posted by karimwassef

Also, how do you keep the plastic clean so that the GHA grows on the screen, not the plastic screen?

Not sure I follow you?

[karimwassef]

This algae doesn't blow off. It's very short haired. I need to grind it off with a very abrasive brush and even then, it persists. My snails struggle. Only urchin get to it but that's because they grind the rock away too.

It only grows at the very top of my tank... Where my tangs have not been able to gain access except during surges.

If I run a horizontal scrubber through my return path next to my MH, the clear duct would be full of water with the screen inside. In that case, I would expect the algae to grow on the inside of the plastic wall before it grows on the screen.

[Floyd R Turbo]

Rocks at the top of the water column like that are going to be tough to out-compete because you have them close to the lighting (intensity) and then add in a surge and you have fast laminar flow that you typically don't see lower in the water column.

The reason I suggested blowing off the rocks is that I was thinking maybe the algae is utilizing a fuel source at or near the rock surface, and blowing this off might remove the source, if you do it often enough, you keep the source low. But if this is near a surge area, that kind of blows that idea away (literally)

So if you're thinking, clear PVC pipe or something like that, with the plastic canvas inserted into it, yes eventually you're going to grow algae everywhere in there, but that will take some time. I think that a vinegar cleaning every 3 to 6 months should keep this at bay, and this assumes that you are going to take that whole thing apart every week or so to remove the algae screen and clean it? Where you will probably also rinse it out and remove any algae that you can get to...so that should help.

Also, scrubbing/brushing the rocks to remove the algae: while this might work, you are also removing all the rest of the surface life (periphyton) and then the process "starts over". I think you're in a bit of a bind here because the rock is so close to the surface/lights. Part of me says to just let it grow and maybe pull off what you can manually without brushing and see if it either burns itself out, or if the scrubber can out-compete it.

[karimwassef]

Glad you feel my pain. It is very brightly lit and with a constant surge, it gets fresh tank water constantly.

Having said that, I did squeeze and scrape some off after some grinding and it release some "stuff". This is like a cloud of particulates and creamy liquid. This mat seems to act like a sponge trapping stuff as the surge flies over it. It's only a few mm thick, but it has pods and other things inside it.

I still want it gone though. My corals can out-compete with it and even grow right on top of it, but it probably slows them down. I have no other algae in the tank, so this brown fuzz is an eyesore. I'd much rather have coralline there.

So - 5' tube of 3" clear acrylic is the game plan. With a long strip 3" x 60" of plastic mesh scoured up - PVC pipe ends and connected to my 2" distribution line. Lit with the MH immediately over it.

Let's see where that goes.

[sensei]

Floyd,
I am having algae problems in my sps tank.
I do not have to many fish so I started dosing oyster every day for coral food. I was testing PO4 and NO3 and it did not show so I continued dosing until a friend made me realize that it did not show because algae was consuming them.
I have made several attempts to control algae:1 blackout, water changes, higher Mag levels and implemented a refugium with chaeto 10 days ago.

algae is better than before blackout but it is still not controlled and keeps growing.
I do not know if I should implement a ATS right away??

I do not feed to much: just 1 cube of myses and 1 sheet of nori and no oyster or any other coral food any more.

can you explain a little more why it is not recommended to scrub algae from rocks with a brush

thanks

[SantaMonica]

Here is why:

What is Periphyton?

Periphyton is what turns your rocks different colors. You know... the white rocks you started with in SW, or the grey rocks (or brown wood) you started with in FW. After several months or years, the rocks become a variety of different colors and textures. Why? Because the periphyton that has grown on it is a mix of different living things, of different colors, and thicknesses. And the important part is: It is LIVING.

That's right: The colored stuff that has coated your rocks is all living organisms. Sponges, microbes, algae, cyano, biofilms, and of course coralline. After all, "peri" means "around the outside", and "phyto" means "plant". Ever slipped in a slippery puddle? That's probably periphyton that made it slippery. It's a very thin coating on the rocks, sometimes paper thin.

There is a lot of photosynthetic organisms in periphyton, and this of course means that they need light; but they need nutrients too (ammonia, nitrate, phosphate). And as you might figure, they will be on the lighted portions of the rocks. And they will grow to intercept food particles in the water, based on the water flow. Just think about how sponges orient their holes for water flow; the micro sponges in periphyton do it too but on a tiny scale.

What about under the rocks, in the dark areas? Well these periphyton don't get light, so they are primarily filter feeders. So they REALLY grow and position themselves to be able to intercept food particles. And they don't really need to fight off algae, because algae does not grow in the dark, so they have no need for anti-algae tactics like plants in illuminated areas have.

Reef studies have shown that at certain depths, more of the filtering of the water comes from periphyton and benthic algae than comes from the phytoplankton which filters the deeper water. And in streams, almost all the filtering is done by periphyton. So, what you have on rocks that are "mature" or "established" is a well-developed layer of periphyton; and all the things that comes from it.

This is why mandarin fish can eat directly off the rocks of an "established" tank (tons of pods grow in the periphyton), but not on the rocks of a new tank. Or why some animals can lay their eggs on established rocks, but not new ones. Or why established tanks seem to "yo-yo" less than new ones. Even tangs can eat periphyton directly when it's thick enough. Yes periphyton can also develop on the sand, but since the sand is moved around so much, the periphyton does not get visible like it does on rocks. So thick periphyton on established rocks is your friend. And totally natural too. Keep in mind though I'm not referring to nuisance algae on rocks; I'm only referring to the very-thin layer of coloring that coats the rocks.

But what happens when you "scrape the stuff off your rocks"? Well you remove some of the periphyton, which means you remove some of your natural filter and food producer. What if you take the rocks out and scrub them? Well now you not only remove more of your natural filter and food producer, but the air is going to kill even more of the microscopic sponges in it. And what if you bleach the rocks? Well, goodbye all filtering and food producing for another year. It's an instant reduction of the natural filtering that the periphyton was providing.

However, what if you just re-arrange the rocks? Well, some of the periphyton that was in the light, now will be in the dark; so this part will die. And some of the periphyton that was in the dark will now be in the light, so it will not be able to out-compete photosynthetic growth and thus will be covered and die too. And even if the light stays the same, the direction and amount of water flow (and food particles) will change; sponges that were oriented to get food particles from one direction will now starve. So since the light and food supply is cut off, the filtering that the periphyton was providing stops almost immediately, due only to the re-arranging of the rocks.

Starvation takes a little longer. The periphyton organisms won't die immediately, since they have some energy saved up; but instead, they will wither away over several weeks. So on top of the instant reduction in filtering that you get by just moving the rocks, you get a somewhat stretched-out period of nutrients going back into the water. And after all this, it takes another long period of time for the periphyton to build up to the levels it was at before: 1 to 2 years. Even changing the direction of a powerhead will affect the food particle supply in the area it used to be pointed at.

So a good idea is to try to keep everything the same. Pick your lighting, flow, layout, and try to never move or change anything. It's a different way of thinking, but you should have a stronger natural filter and food producer because of it.

[karimwassef]

I get that, but even nature isn't fixed... Storms, fish, even changing flow patterns.

I think the problem is that we're not dynamic enough. So instead of robust life, we have fragile life that withers at the slightest change.

Same basic facts - but alternate interpretation?

[jason2459]

Nature has one very large advantage compared to our very small closed system.

But I also see where you are coming from but I would pose a middle ground of consistency. Consistency doesn't necessarily mean constant. If the forums and over 3 decades of reefkeeping shows us is that our animals will adapt to most anything. We've seen so many successful reefs put into use so many various methods, equipment, foods, parameters, supplements, chemicals, schedules, etc etc. One common thing is they all seem to strive for is consistency in what they do.

[sensei]

Originally Posted by SantaMonica

Here is why:

What is Periphyton?.

Thanks Santa Monica for the very explicit explanation. I never though all the implications in scrubbing the rocks.

Any comments on my other question:

Originally Posted by sensei

Floyd,
I am having algae problems in my sps tank.
I do not have to many fish so I started dosing oyster every day for coral food. I was testing PO4 and NO3 and it did not show so I continued dosing until a friend made me realize that it did not show because algae was consuming them.
I have made several attempts to control algae:1 blackout, water changes, higher Mag levels and implemented a refugium with chaeto 10 days ago.

algae is better than before blackout but it is still not controlled and keeps growing.
I do not know if I should implement a Algae scrubber right away??

I do not feed to much: just 1 cube of myses and 1 sheet of nori and no oyster or any other coral food any more.

thanks

[Floyd R Turbo]

I would say that an algae scrubber will likely do a better job of pulling nutrients out vs the chaeto, but that depends on how both the refgium and scrubber are constructed and maintained.

For the amount you are feeding, a 2-3 cube/day scrubber should do (24-36 sq in)

[sensei]

Thanks Floyd,
24 -36 sq in illuminated both sides correct?
but since it is somewhat small, it could be better to do a 8 x 8 inch scrubber and illuminate it only from one side. I am thinking of using a 2700K CFL reflector
please tell me what do you think?

[Floyd R Turbo]

Lit on both sides is always better because you can let it grow longer between cleanings, which means more growth (it's not a linear growth/day curve, it's more like an exponential curve)

You can go 8x8 and then play with other factors to adjust the effective "capacity" of the scrubber, such as flow, lighting photoperiod, proximity of the lights (1" change can make a big difference), etc. If you are trying to match your screen to your lights, which is usually the case with CFLs, then going a bit bigger is generally OK, but you can configure the lights to match the screen. you don't have to go with a dome-type reflectors, you can turn the CFL lamp sideways and use a curved reflector on the back side and that works better actually.

[sensei]

Originally Posted by Floyd R Turbo

Lit on both sides is always better because you can let it grow longer between cleanings.

I am not sure I understand why you can let it grow longer?
when I clean it should I remove all the algae from the scrubber?

how far should I put the CFLs from the screen in each side?
should I start with a 18 hour photo period and 4" away from canvas?

since I will be using CFLs should I do 8x 8 although 6 x 6 is enough?
thanks for your help

[Floyd R Turbo]

a single sided scrubber will self-shade faster than a double-sided scrubber. The small amount of light that gets through to the base from both sides is enough to prevent detachment for a longer period of time, so you can go longer between cleanings without die-off. The longer you can go between cleanings, the higher the rate of mass increase can be. This is why a double-sided scrubber is almost always better.

Distance from CFLs to screen is generally about 3-4 inches, but it depends on the lamp and fixture (wattage and reflector)

I would start with 12-16 hours/day and see how your initial growth is. If you start to get good coverage quickly, then you can increase to 18. The initial break-in period is the 'finicky' time. Once you get past that, you can ususally run longer hours and possibly move the light a bit closer

Either size should work, 8x8 should be fine, you just might not grow much around the edges so it may effectively be the same capacity, again, depending on how you build your lighting

[sensei]

thank Floyd,

I will let you know how it goes