Skimmer on a timer

[zoanutty]

I'm currently running a 240 with an 80 gal fuge and a fairly large reef octo skimmer which I just got. My tank is 50% zoas, 40% lps & 10% sps (mainly montis & chalices, no sticks). Because of this, I was thinking of putting the skimmer on a timer since 1) the skimmer is so big (rated for 300 gal) and 2) zoas and lps do not require a pristine tank. But I am wondering if in doing so I stand to mess with my tank chemistry, particularly ph & alk. I dose cal & alk via doser 3 x day 20 ml each time. Any thoughts or suggestions would be appreciated.

[bertoni]

The pH might show more extremes, but alkalinity will not be affected. I would keep the skimmer running, in case of emergencies, but lots of tanks run without skimmers at all.

[ReefsandGeeks]

I'd run the skimmer constant myself. That way you don't have to deal with pH swings or the skimmer not priming or whatever. If you want slightly dirtier water, just run the skimmer dryer untill you get the balance you want. It'll also give you the added benefit of emptying the skimmer less often.

[nuxx]

Never a bad thing to leave the skimmer on all the time.

Let it skim drier if you think it's overkill...

[zoanutty]

Thanks for your help guys!

[tmz]

I run it 24/7 fwiw. If I need to shut the skimming off for a period of time for supplements or medications ,I disconnect the airline and let the water keep flowing to limit the risk of stagnation in any still water in the skimmer.

[karimwassef]

I run 18 hrs on / 6 hrs off. The purpose is to give plankton life in the water column an opportunity to survive.

I think it works great.

[nuxx]

I run 18 hrs on / 6 hrs off. The purpose is to give plankton life in the water column an opportunity to survive.

I think it works great.

Wouldn't you think a lot of "life" misses the skimmer? I mean it only gets what goes through the pump.

[karimwassef]

It depends on how much you pass through your skimmer. My skimmer inlet pump is running 2000gph. If it's enough to filter the water, then it's catching a lot of the life in the water column too.

[nuxx]

It depends on how much you pass through your skimmer. My skimmer inlet pump is running 2000gph. If it's enough to filter the water, then it's catching a lot of the life in the water column too.

Gotcha :)

Ours is only running around 600.

[davocean]

24/7 really is best and it's actually easier on most pumps to just run rather than start up all the time from my reading.
FWIW we all pretty much run skimmers oversize to our tanks more than what manufacturers call out for.
A skimmer rated for 300g on a 240g is nothing, some people almost double that, especially depending on what your bioload is.

[tmz]

I think the water volume moving trough the skimmer and the amount of bubble surface area matter a lot in terms of total export and gas exchange.

24/7 is my preference with two ASM 4xx skimmers on a 650 gallon system . Each has a needle wheel wheel ,which produces copious fine bubbles via a sedra 15000 pump rated at 1500gph per hour ,for a total water movement of 3000 gph , which turns over the 650 water volume nearly 5xs per hour. Each is rated for up to 500gallon systems.

There is still always plenty of plankton in the water . Much of it has life cycles with phases that are benthic.

IMO turning of the skimmer pump for significant periods of time with stagnant water in the skimmer column is an unnecessary risk. Not much if any plankton is going to propagate in 6 hours anyway. The loss of aeration for significant periods of time will also cause a lack of constancy in gas exchange and potentially lead to hypoxic conditions in areas of the tank.

If I were inclined to stop skimming for a period of time, I'd just close off the air flow ,stopping the bubble formation, and let the water pump keep going. Even then the loss of aeration is a concern.

[karimwassef]

There was a you tube experiment run over 6 identical tanks to look at coral health. The ones with the skimmer off at night did best.

It's a function of your feeding, etc... But I can see the impact on living plankton in my tank of being off at night.

Try it and compare your coral growth rates ... Data speaks best.

[tmz]

I seriously doubt there is any real any data to show shutting down the skimmer particualrly at at night when CO2 levels are high and oxygen is lower encourages growth given the fact that photosynthesis stops at night is best. My corals grow just fine and it makes no sense to me to cut down aeration given the potential for nightime hypoxia. We disagree.

[karimwassef]

We do. I have no issues with pH or oxygenation. I have a large surface area and dose kalk that keeps my pH at 8.3 day or night.

[davocean]

I seriously doubt there is any real any data to show shutting down the skimmer particualrly at at night when CO2 levels are high and oxygen is lower encourages growth given the fact that photosynthesis stops at night is best. My corals grow just fine and it makes no sense to me to cut down aeration given the potential for nightime hypoxia. We disagree.

Totally agree, if anything at night you will benefit from leaving it on.

[tmz]

Folks can make up their own minds;you obviously have no data.

I'd suggest they take a look at some of the posts you've made.The only thing I see is a tank wrought with one tragedy after another;no data or insight , and some advice I think is really bad and harmful in a number of areas. Going back just a couple of weeks I found these gems :

velvet treated with uv;fish died but it helped so it must be good for dinoflagellates.
infesting the tank.

Favia bleaching but I got the tentacles to come out.

Ideal temp for coral growth. I'd like it as hot as I can 90 F would be good. At 84F fish breathing heavy.

Or this one showing your tank just 2 weeks ago:

http://www.reefcentral.com/forums/showthread.php?p=23727724#post23727724 lot's of corals bleaching.

There are plenty of other examples going back a bit further.

It makes me sad that you are having so much difficulty . But if you don't wan't to listen so be it. I do hope folks take a critical look at your advice or just ignore lest they get similar results. Personally, I won't make the effort to offer you advice or answer any questions from you any longer but will challenge bad advice and information when you post it.

[karimwassef]

Rescue corals from a local reef keeper getting divorced but thanks for the personal attack.
Lack of quarantine causes marine velvet. Surprise.

I only post failures to look for help, there's no point in posting successes.

My tank is actually in great shape. Shame that you think you know someone from reading posts looking for answers in absence of context.

<a href="http://s1062.photobucket.com/user/karimwassef/media/BCFE8C4A-3D37-48D4-B138-3601FFE61E29_zpshfjel3x5.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/BCFE8C4A-3D37-48D4-B138-3601FFE61E29_zpshfjel3x5.jpg" border="0" alt=" photo BCFE8C4A-3D37-48D4-B138-3601FFE61E29_zpshfjel3x5.jpg"/></a>

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<a href="http://s1062.photobucket.com/user/karimwassef/media/D33F8EAB-AC0C-48F2-A3BB-C5395E221055_zps3csm2fe4.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/D33F8EAB-AC0C-48F2-A3BB-C5395E221055_zps3csm2fe4.jpg" border="0" alt=" photo D33F8EAB-AC0C-48F2-A3BB-C5395E221055_zps3csm2fe4.jpg"/></a>

<a href="http://s1062.photobucket.com/user/karimwassef/media/194D6722-6E17-435D-948E-32B969BA6F29_zpszqqhd2co.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/194D6722-6E17-435D-948E-32B969BA6F29_zpszqqhd2co.jpg" border="0" alt=" photo 194D6722-6E17-435D-948E-32B969BA6F29_zpszqqhd2co.jpg"/></a>

[karimwassef]

And here is the favia before I had it in my tank long

<a href="http://s1062.photobucket.com/user/karimwassef/media/DBD2E747-AFD9-4846-BBAA-A47F7357CE68_zpsq08zw6pq.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/DBD2E747-AFD9-4846-BBAA-A47F7357CE68_zpsq08zw6pq.jpg" border="0" alt=" photo DBD2E747-AFD9-4846-BBAA-A47F7357CE68_zpsq08zw6pq.jpg"/></a>

[karimwassef]

Here it is AFTER

<a href="http://s1062.photobucket.com/user/karimwassef/media/55E2435B-344C-4B72-94F6-C05AC61D4307_zpsqrzfzcqx.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/55E2435B-344C-4B72-94F6-C05AC61D4307_zpsqrzfzcqx.jpg" border="0" alt=" photo 55E2435B-344C-4B72-94F6-C05AC61D4307_zpsqrzfzcqx.jpg"/></a>

[karimwassef]

My method works. Resorting to personal attacks shows some serious lack of confidence in your approach.

Make sure not to listen to anyone other than the sound of your own voice.

[karimwassef]

<a href="http://s1062.photobucket.com/user/karimwassef/media/12FC3480-F6AD-4B01-874E-79C0C9919307_zpsqan5ta0u.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/12FC3480-F6AD-4B01-874E-79C0C9919307_zpsqan5ta0u.jpg" border="0" alt=" photo 12FC3480-F6AD-4B01-874E-79C0C9919307_zpsqan5ta0u.jpg"/></a>

<a href="http://s1062.photobucket.com/user/karimwassef/media/EDB03D10-AD54-4C32-A0C4-D4D0316090D8_zpsnq6suodb.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/EDB03D10-AD54-4C32-A0C4-D4D0316090D8_zpsnq6suodb.jpg" border="0" alt=" photo EDB03D10-AD54-4C32-A0C4-D4D0316090D8_zpsnq6suodb.jpg"/></a>

That's about 3 months worth.

By the way, I make mistakes and I travel, so bad things do happen... I lost salinity for a week, and most actually survived...

My reef is ten months old, and still demonstrating resilience and growth.

[karimwassef]

Frags March 22nd
<a href="http://s1062.photobucket.com/user/karimwassef/media/24A421FD-4DC2-4EF3-B15E-F2A4C44F0EE0_zps8eedmdhf.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/24A421FD-4DC2-4EF3-B15E-F2A4C44F0EE0_zps8eedmdhf.jpg" border="0" alt=" photo 24A421FD-4DC2-4EF3-B15E-F2A4C44F0EE0_zps8eedmdhf.jpg"/></a>

Two months later
<a href="http://s1062.photobucket.com/user/karimwassef/media/603FDBCC-BB74-48E5-874B-1CD042E77003_zpsadz8orni.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/603FDBCC-BB74-48E5-874B-1CD042E77003_zpsadz8orni.jpg" border="0" alt=" photo 603FDBCC-BB74-48E5-874B-1CD042E77003_zpsadz8orni.jpg"/></a>

[karimwassef]

April 16th
<a href="http://s1062.photobucket.com/user/karimwassef/media/6F26DF8C-BA14-4E00-9DF4-16C47ECAC11E_zpsdsevux8h.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/6F26DF8C-BA14-4E00-9DF4-16C47ECAC11E_zpsdsevux8h.jpg" border="0" alt=" photo 6F26DF8C-BA14-4E00-9DF4-16C47ECAC11E_zpsdsevux8h.jpg"/></a>

May 20th (a month later)
<a href="http://s1062.photobucket.com/user/karimwassef/media/DDF16323-92AA-48A2-BA33-F73A267276A4_zpsexgypfmj.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/DDF16323-92AA-48A2-BA33-F73A267276A4_zpsexgypfmj.jpg" border="0" alt=" photo DDF16323-92AA-48A2-BA33-F73A267276A4_zpsexgypfmj.jpg"/></a>

[karimwassef]

I can't find the video showing the experiment with intermittent skimming, but I'll keep looking for it.

[karimwassef]

http://youtu.be/4iSW_GPP9ac

http://www.reddit.com/r/ReefTank/comments/2lj86h/1_year_experiment_of_four_identical_tanks_with/

I didn't make it up. Just took some digging.

To the OP - this hobby is full of those who will put everything they don't use down. Do the research and experiment yourself.

I ran a 24/7 skimmer from the 90s until 2014... It works and it works well. For me, I found better results with a part time skimmer.

[tmz]

It's not personal; it's just bad information and poor quality.

[davocean]

[QUOTE=karimwassef;

To the OP - this hobby is full of those who will put everything they don't use down. Do the research and experiment yourself.
[/QUOTE]

This hobby and site also has no shortage of people that ignore facts and pass on bad info, but I don't normally see that coming from RC staff members or long term hobbiests.

[bertoni]

[flamealert]

Okay, let's keep this conversation civil. The tone seems headed a bit downhill.

[tmz]

Lest folks be misled . There is no data in the links. More or less a pitch for buying mud as far as I can tell. Hardly worth echoing.IMO . Even so I didn't see any mention of turning off the waer flow to the skimming timeframes.

These are a few random shots of my corals that have grown from small frags with years of 24/7 skimming:

http://s229.photobucket.com/user/fishandfootball58/media/tanks%202012/SDC10203.jpg.html?sort=3&o=40

http://s229.photobucket.com/user/fishandfootball58/media/tanks%207%2013/SDC10185_zpsa55075cf.jpg.html?sort=3&o=23

BTW. I also run tanks with light and no skimming for corals with higher heterotrophic needs like capnella ,discoma and and xenia ;sps don't do nearly as well in those tanks,ime.

Shutting off the skimmer feed pump for subtrantial periods of time reduces aeration and gas exchange and leaves relatively stagnant water in it. Using a smaller skimmer or simply valving off the air flow for periods of time is a safer course if lyou ae set on reducing skimming.

[karimwassef]

I run 18hrs on / 6hrs off. I don't see that as an exceptionally long period of off time.

My pH is controlled with Kalk addition on an Apex - set to a constant 8.3, so it never dips. My Alkalinity ranges from 8 to 9.5dKH and Calcium from 420 to 500. I do manual A/B additions.

Given the surface area (96" x 34") and the surface waves, I don't see any signs of a loss of oxygenation or an increase in CO2.

I don't use mud. I do use a DSB and refugium with Chaeto in my sump. This is constantly pod rich.

I also have an actuated surge that moves a lot of water during the day.

I've experimented with turning my skimmer off at different times (day vs. night, dawn vs. dusk, etc...) and I've also run constant on 24/7 and skimmerless.

I've found that turning it off at dusk (3 hours end of day and 3 hours at night) resulted in the greatest polyp extension at night. That's not the only measure of health, but my growth is visible in my previous posts.

[karimwassef]

another variable may be the size of my skimmer and the flow through it
It's a DIY 12ft recirculating beckett injected style with 2000gph through it.

<a href="http://s1062.photobucket.com/user/karimwassef/media/Mobile%20Uploads/BBC3548B-3CF2-44DF-9B5C-65B388EAFB33_zpshpfnzb51.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/Mobile%20Uploads/BBC3548B-3CF2-44DF-9B5C-65B388EAFB33_zpshpfnzb51.jpg" border="0" alt=" photo BBC3548B-3CF2-44DF-9B5C-65B388EAFB33_zpshpfnzb51.jpg"/></a>

The skimmer cup is up at the garage ceiling

<a href="http://s1062.photobucket.com/user/karimwassef/media/150E3439-8215-4489-A1B9-3D625F319C26_zpske5ttiv1.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/150E3439-8215-4489-A1B9-3D625F319C26_zpske5ttiv1.jpg" border="0" alt=" photo 150E3439-8215-4489-A1B9-3D625F319C26_zpske5ttiv1.jpg"/></a>

[bertoni]

This hobby is very complicated, and we have a very limited amount of hard data to guide us. This section of Reef Central is supposed to be science-oriented, so we try to keep a fairly strict line on quality of data. I agree that the data here in favor of part-time skimming is very limited, and anecdotal in nature.

Personally, my skimmers ran 23 hours a day. I shut them off for 1 hour after feeding phytoplankton, so that the skimmer didn't remove as much of the algae I was adding. Less skimming might leave more micro plankton in the water column, which could be good. The down side is that aeration is reduce, and the skimming "safety net" is gone. I don't know what the relative tradeoffs are.

[karimwassef]

So. The video I found shows 4 tanks being run with the same controls but with a few variables changed... for a year. How many of us have done that?

I agree it's not scientific, but that's a lot of effort for a hobbyist. He should have measured his parameters, logged them, etc... But I wouldn't dismiss it outright either. He could be making it all up, but wow- that's a lot of effort to put people on the wrong track.

For aeration, are we saying that skimmerless tanks run low on oxygenation and so can't be successful? Doesn't that depend on the exposed surface area and wave motion too?

I've personally never had a long term skimmerless tank - the longest was a week while fixing a leak in mine.

[bertoni]

Lots of people run skimmer-less tanks successfully, so it's very clear that skimmers are optional. That said, they do offer advantages, especially for tanks near the higher end of the bio-load range and in cases of emergencies, like some mass spawning events. I ran a skimmer-less tank for a few months, at least, although my experiences with it were negative.

[karimwassef]

Did you use an alternative export method like chaeto or more frequent water changes?

[bertoni]

I did try more water changes and ran carbon, but one of my soft corals wouldn't open until I added a skimmer. I turned the skimmer off for a few days a couple more times, to try to test the effect. It closed up every time. My best guess is that another soft coral was producing allelopathic toxins.

[tmz]

Lots of people run skimmer-less tanks successfully, so it's very clear that skimmers are optional. That said, they do offer advantages, especially for tanks near the higher end of the bio-load range and in cases of emergencies, like some mass spawning events. I ran a skimmer-less tank for a few months, at least, although my experiences with it were negative.

I agree skimmers are optional and some seem to have some success without them. For some corals less to no skimming actually seems to be a benefit; for many others particulary sps it's not the case ,IME .
I don't think turning one off for an hour is a problem in terms of stagnation or lost aeration. I do that when I feed small particle foods or amino acids on rare occasions When I medicate or otherwise need to stop skimming for a longer period , like with interceptor for 12 hours , I'll leave the skimmer flowing to avoid stagnant water but disconnect or valve of the air intake .No bubbles > no skimmming . I'll add a few airstones to make up some of the lost aeration.

I agree plankton is likely very helpful as a food source but see plenty of it at night even when skimming . The organic carbon I add may be helping the food web. Many corals can be target fed during the day too.

[tmz]

For those using calcium hydroxide(klak). It's a source of calcium and alkalinity. It uses CO2 to make CO3 thus continuously reducing CO2 levels in the tank as they equilibrate with the surrounding air . More CO2 equals lower pH. Turning a dsoing device on and off as suggested in another post to respond to preset tank pH level puts constancy in alk and calcium levels behind maintaining pH. A diurnal swing in pH much less conerning than bouncing alk around for sps. It's a cart before the horse scenario. On off dosing can also contribute to equipment failure and clogging.

[karimwassef]

Since I run a recirculating Beckett, I can cut the circulating pump and get no bubbles. The main flow would continue.

My skimmer's intake and outlet are both in my sump - different stages. But I'm moving the return to the DT directly since my cup is 5 feet over the DT water level.

I'll try cutting the recirculating pump only but keep my flow pump on. I've been looking for a way to increase return flow, so this should work very well.

[karimwassef]

My alk and calcium are always just shy of optimal with a pH of 8.3...I still manually dose to get to my target.

I experimented with different pH set points from 8.2 to 8.6 (before I had corals in the tank) and measured alkalinity over time. The pH of 8.3 gave the best balance of maintaining calcium and alkalinity close to target, but not over it.

I don't use a dosing device. I use a gravity feed of RODI water through a solenoid that has no issues being turned on and off at any duty cycle. The water flows into my kalk reactor and the overflow goes into my tank. Running for 6 months constantly with no issues.