Skimmerless: who's doing it? pros and cons

[AcroporAddict]

haven't used a skimmer since the nineties. i run air, water changes, almost daily.
four gallon and a two point six gallon.

With tanks that small, I would not run a skimmer either.

 

[Plantbrain]

I run a fuge at full biomass. N and P are not an issue, organics, a sack of carbon here and there. This does NOT bother the macro algae growth. I also make sure to balance the macro algae biomass, you do not add a tiny bit and then watch is grow and grow and then crash once it eats itself out of house and home, you have to trim and remove biomass to keep it looking and performing well. Generally I keep between 40-50% max biomass that fills the space I have for the macro algae. I'll let it get to about 90% or so, then hack it back. Unlike skimmate and most ATS's, I can sell and do other things with the macro algae. I can also pick and chose which interesting species of macro algae I grow. That's 50-100 species easily. oem work better than others, but I like macros also.

You do not want to bottom out the N and P, then the macro algae do not grow and the corals do not do as well IME. That's what causes more(the most?) problems with folks using macros in their fuges. They melt, go sexual, frag etc.........if you bottom things out and they starve. You do not want feast or famine, you want good consistent trimming of the biomass. Then you get good consistent nutrient export. You can combine this with a DBS also. The macro algae also provide an excellent source for reduced carbon that in turn, help bacteria mineralize organic waste much better. Macros naturally leach a significant % of their photosynthate. You can change the water often or not..........whatever management methods works best for you, as the tank gets bigger, the cost of salt mix goes up. So dosing and checking paramaters might be of use. I'm in the middle there, so I do water changes on the smaller tank, and a dosing on the larger. Since the coral and the macros are pretty responsive to the routines, you can use them as a test kit if you are fairly well experienced.

Eg, like Hex's 155:
calcium, alk, mag, strontium, potassium, iodine, essential elements, occasional amino acids

Ca and alk for testing mostly, then light dosing on the others.
I do something similar for the larger tank.
I'll be messing around more with this in the coming months.

 

[rounder45]

folks... skimmerless on a tiny tank is a no brainer... seriously...LMFAO...

 

[Plantbrain]

I experimented without my skimmer for several months. The primary issue that was immediately apparent was that the pH rose too much. I use limewater, and without the skimmer to aerate and bring in adequate CO2, the pH was too high.

This raises an interesting question, why not use a wet/dry if degassing CO2 is an issue and keeping a more stable O2? Nitrogen is pretty lean already in such systems, and the macro algae would suck that up as NH4 or NO3 and also stabilize CO2 for the marine macros/plants.

Seems a simple passive gravity fed method is a lot simpler and cheaper over time than a skimmer. Skimmer has some advantages, but if it's mostly to deal with O2/CO2, then a wet/dry seems to fulfill this role. N is not much of an issue if you have a good sized refugium and decent macro growth.

Wet/dry towers are pretty much maintenance free for years, not many skimmers can make that claim. Obviously skimmers have other advantages, but on this point?

I tend to run larger refugiums, so the biomass and DBS are pretty intense for nutrient removal rates relative to the loading rates from the main tank. I think I'll add a smaller tower back. I have a Hach HQ40 with the LDO and a pH probe, so I should be able to quantify to the before and after addition pretty easily over a 24 hour cycle.

I'm trying to avoid some equipment and am a reductionist generally with methods.

 

[ktownhero]

I never even considered a skimmer for my 20L nano that ran successfully for 8 years with softies and light fish load. I just used an aquaclear filter (as a mini fuge) and 1 power head. Easy peasy tank, just did water changes when I felt like it which sometimes meant months apart.

Can't speak for larger tanks, but if I were doing another nano I'd do it the exact same way.

 

[tmz]

I think a wet and dry filter does add water surface to air interface areas like a skimmer does. I have no idea how to quantify which is more efficient at this particular function.
The surface areas in a wet and dry do ,however, encourage ammonia oxidizing nitrifying bacteria to grow there producing nitrate; a skimmer does not.

If the wet and dry feeds an adequately sized and lit macro algae refugium along with adequate phosphate and iron the nitrate might not become an issue in the tank. Excessive alge e exudate and total organic carbon might be an issue.

 

[tmz]

I never even considered a skimmer for my 20L nano that ran successfully for 8 years with softies and light fish load. I just used an aquaclear filter (as a mini fuge) and 1 power head. Easy peasy tank, just did water changes when I felt like it which sometimes meant months apart.

Can't speak for larger tanks, but if I were doing another nano I'd do it the exact same way.

Different corals do better or worse with less skimming ( higher organic content in the water) ,IME. . Some have high heterotrophic needs and seem to rely on absorbing organic materials from the water for much of their feeding.

FWIW, I run a 65 gallon and 30 gallon loaded with xenia, capnella , discoma, elephant ear mushrooms , gorgonia, gsp, various palythoa and zooanthus ,entamacea ( bubble tip anemones and fish.

The main sps dominated mixed reef tanks are heavily skimmed.

 

[Fredfish]

... Some have high heterotrophic needs and seem to rely on absorbing organic materials from the water for much of their feeding...

I'm not convinced of that. Anything with a mouth and feeding tentacles has them for one reason only: prey capture.

Now, it could be that some corals are more able to absorb what they need.

 

[greyreef]

Im interested in getting a crytic refuge functioning for my tank
Had a blacked out zone in my original refuge with rock, but my original sump leaked, got a great acrylic one but it doesnt have room for cryptic...

Have my cryptic rock in a separate tub, will be connecting to my sump shortly
Think thats a better idea as far as cleaning and maintanence is concerned

Questions for everyone after reading this thread...

If you do go skimmerless (as I have from the beginning) and eventaully as you build up corals, need to dose things, wouldnt it be better to use 2 part, to eliminate the drop in pH you get with kalk...

Also, those with cryptic refuges, how often and how do you clean?

 

[tmz]

Some of corals with a higher heterotrophic needs to supplement photosynthesis just do better in lightly skimmed water IME ;maybe they take in bacteria or other small micro fauna or particulate matter and/or dissolved organic matter through their mouths otherwise removed in a heavily skimmed system or absorb it in some other fashion .

The tentacles on some may do a lot more than just capture prey btw . Xenia for example pulse without evidence of taking up prey. While their feeding mechanisms are largely unknown, they are thought to pulse to help mix the water around them for optimal CO2 and oxygen levels for photosynthetic activity as well as for expulsion of gases.

Mouths take in many things like bicarbonate ,calcium ,dissolved organic material and also serve as a portal to expel excesses. Prey capture is certainly part of the deal for many but not necessarily enough for all in a partiuclar aqarium.

I should note, zoanthids do well in heavily skimmed water . . Mine do ok in the unskimmed tanks but seem to do best in a heavily skimmed tank boosted along with organic carbon dosing. Maybe they like bacteria.

So, less skimming may have advantages for certain speices, imo. However a lack of skimming , may be deterimental to corals sensitive to high total organic carbon content. In any case skimming does aerate significantly.

Some corals come from turbid water on reef flats l with dissolved orgnanic and small particualte orgnic material and some of those might have difficulty in a tank with low orgnaic content.

 

[Aquarist007]

Some of corals with a higher heterotrophic needs to supplement photosynthesis just do better in lightly skimmed water IME ;maybe they take in bacteria or other small micro fauna or particulate matter and/or dissolved organic matter through their mouths otherwise removed in a heavily skimmed system or absorb it in some other fashion .

The tentacles on some may do a lot more than just capture prey btw . Xenia for example pulse without evidence of taking up prey. While their feeding mechanisms are largely unknown, they are thought to pulse to help mix the water around them for optimal CO2 and oxygen levels for photosynthetic activity as well as for expulsion of gases.

Mouths take in many things like bicarbonate ,calcium ,dissolved organic material and also serve as a portal to expel excesses. Prey capture is certainly part of the deal for many but not necessarily enough for all in a partiuclar aqarium.

I should note, zoanthids do well in heavily skimmed water . . Mine do ok in the unskimmed tanks but seem to do best in a heavily skimmed tank boosted along with organic carbon dosing. Maybe they like bacteria.

So, less skimming may have advantages for certain speices, imo. However a lack of skimming , may be deterimental to corals sensitive to high total organic carbon content. In any case skimming does aerate significantly.

Some corals come from turbid water on reef flats l with dissolved orgnanic and small particualte orgnic material and some of those might have difficulty in a tank with low orgnaic content.

Zoos are the only coral that have been affected negatively by carbon dosing. Slowly dying off.
Since bacteria is part of TOC which affects skimming rates. I wonder if skimming increased skimming rates are also removing an organic that zoos want

 

[tmz]

If you do go skimmerless (as I have from the beginning) and eventaully as you build up corals, need to dose things, wouldnt it be better to use 2 part, to eliminate the drop in pH you get with kalk...

Kalk is calcium hydroxide, it increases pH ;it doesn't drop it. The hydroxide OH uses CO2 in the tank to form carbonate( CO3) which is carbonate aloakinity. Less CO2 equals higher pH.

Also, those with cryptic refuges, how often and how do you clean?

Once year or so.

 

[tmz]

Zoos are the only coral that have been affected negatively by carbon dosing. Slowly dying off.
Since bacteria is part of TOC which affects skimming rates. I wonder if skimming increased skimming rates are also removing an organic that zoos want

Zoanthus do better with carbon dosing than wihtout it in my tanks which have been dosed with vodka and vinager for 5 plus years. I think they might eat the bacteria. Palys still beneift from food in the water.

 

[acorral]

Now that someone brought up the zoanthids... Since I went skimmerless with ATS my zoas have gone downhill... Also the green star polyp colonies I had are almost gone... Palys just stopped reproducing and SPS are thriving live never before.

 

[Timfish]

. . . Also the green star polyp colonies I had are almost gone . . .

I don't see this as a problem :lol: Only twice have I specifically tracked the growth rate of a green zoa and a P. grandis variety in both the "donor" tank with a skimmer and in my skimmerless tank and in both cases I saw better growth skimmerless but in neither case was there an ATS.

 

[Randy Holmes-Farley]

This raises an interesting question, why not use a wet/dry if degassing CO2 is an issue and keeping a more stable O2? Nitrogen is pretty lean already in such systems, and the macro algae would suck that up as NH4 or NO3 and also stabilize CO2 for the marine macros/plants.

Seems a simple passive gravity fed method is a lot simpler and cheaper over time than a skimmer. Skimmer has some advantages, but if it's mostly to deal with O2/CO2, then a wet/dry seems to fulfill this role. N is not much of an issue if you have a good sized refugium and decent macro growth.

Wet/dry towers are pretty much maintenance free for years, not many skimmers can make that claim. Obviously skimmers have other advantages, but on this point?

I tend to run larger refugiums, so the biomass and DBS are pretty intense for nutrient removal rates relative to the loading rates from the main tank. I think I'll add a smaller tower back. I have a Hach HQ40 with the LDO and a pH probe, so I should be able to quantify to the before and after addition pretty easily over a 24 hour cycle.

I'm trying to avoid some equipment and am a reductionist generally with methods.

If nitrate is not a concern, and you do not want to skim for some reason, then that may be a fine plan.

 

[Plantbrain]

If nitrate is not a concern, and you do not want to skim for some reason, then that may be a fine plan.

I like the Refugiums and macros/plants more than a skimmer. I find them more interesting from a biology standpoint. And if I did not like biology, well, I likely should not be an aquarist

That said, I've added Ca(NO3)2 2x a week and extra food for the shrimp/cleaning crew. About 3 ppm per dose. It's all been removed for a number of weeks now.

I think I'll modify the sump some and see how things do. I think the macros will grow better, thus handle more input from the main tank. SPS frags seem to be doing well.

I have phased out the inorganic dosing for N since adding the SPS and feeding things more. So far, so good, but thanks for giving me an idea how to improve things more.

 

[Plantbrain]

I think a wet and dry filter does add water surface to air interface areas like a skimmer does. I have no idea how to quantify which is more efficient at this particular function.

O2 and pH, start in a system like a macro run refugium and shut off the water flow for a bit, maybe 1 hour, the pH will go up. Particularly under high light.
So will the O2.

Turn flow back on.
Measure pH drop and O2 drop with the Wet/dry and then with the skimmer.

Standardizing skimmers and/vs wet/drys? Pretty tough. So I could do this for my system.......but it would not be applied well under most anyone else's system. Many variables when it comes to gas exchange rates.

I suppose if you did this for say 6-10 tank systems, and there was a clear pattern..........then perhaps you could generalize.........

The surface areas in a wet and dry do ,however, encourage ammonia oxidizing nitrifying bacteria to grow there producing nitrate; a skimmer does not.

You still have N floating around, NH3:NH4 or NO3.
Unless..... the skimmer skims and removes the NH3:NH4 but does not NO3 (I would expect a skimmer to do that).

Macro algae are not that picky about either form, they will take up both. Some have suggested a mix of both NH4 and NO3 will give higher yields and basically cover both your bases on perfered form and N substrates.

http://escholarship.org/uc/item/0xs3w4s5

This is also true for Freshwater and land plants.
A mix of both forms of N, a ratio is optimal rather than "either" "or".

I'm not sure that's an issue with a wet/dry really.

[/quote]
If the wet and dry feeds an adequately sized and lit macro algae refugium along with adequate phosphate and iron the nitrate might not become an issue in the tank. Excessive alge e exudate and total organic carbon might be an issue.[/QUOTE]

Folks that dose vinegar and booze.............they are adding reduced carbon to help amplify the strong reduced carbon limitation on bacteria.........would not algae leaching provide the same reduced carbon source?

Seems so.

But I'd argue this may simply be the effects of a goldilocks thing with DOC.
Too little = bad
Too much= bad
Nice low residual= good.

Lots and lots of macros= more and more DOC.
Water changes, activated carbon etc can remove those.
But now the skimmer's attributes become better except for smaller system or where the hobbyists does not mind the water changes. Can skimmers effectively remove DOC produced by macro algae in a reef system?

I think you hit the best argument in favor of skimmers vs a refugium here.
N forms can be addressed,Gas exchanges, but DOC needs other management.
Or does it?

How many have correlated DOC(by actually measuring it) with poor growth of corals?

This paper suggest a good mechanism and argument for DOC being the root issue. Does this apply to reef aquariums?


file:///C:/Users/Tom%20Barr/Downloads/Kline%20-%20DOC%20and%20coral%20death%205-24-06.pdf

See figure 4, this would be a good model argument for skimmers versus a skimmerless system. It gives some ranges for DOC

Thanks

 

[Randy Holmes-Farley]

We need a better link as that one is to your computer.

Folks that dose vinegar and booze.............they are adding reduced carbon to help amplify the strong reduced carbon limitation on bacteria.........would not algae leaching provide the same reduced carbon source?

Seems so.

Probably, but not as much (meaning less for bacteria) and perhaps not all as benign since of those are yellow, some may be toxins etc.

 

[Plantbrain]

Allelopathy has little if any evidence in intact FW systems with plants and algae.
And the same issue seems to exists with marine macro algae and coral.
Extracts and test wells versus living material

http://link.springer.com/article/10.1007/s00338-011-0747-1

DOC's can easily be removed using activated carbon(AC). This provides a control for a test claiming allelopathic chemicals or that DOC's are bad for coral health/growth, kill corals, etc.
Water changes can also help, but then that's another factor added. As many hobbyists have and do use AC............and have macros, have we seen a good deal of evidence either way about DOC build up and coral health?
High loading rates from food, decay etc, the labile forms of reduced carbon, these will be different compared to macro algae leachates. Labile forms of DOC lower O2 levels, but these are not an issue if you run a skimmer or have a wet/dry biotower.
Whereas recalcitrant DOC.......likely have a different impact.

A skimmer would remove both types of DOC, whereas the skimmerless would not.