overskimming?

[mandarinfanatic]

can we really overskim our tanks or do we underskim?

 

[spieszak]

My opinion on the subject is that is is POSSIBLE to over-skim. Some will argue that point. The caveat to that is that I also think that its usually out of the reach of most hobbyists to do so, due to both equipment prices and available space.

 

[LouH]

I just went through an experiment on my 30 gallon soft coral tank in which I replaced an Aqua-C Remora HOB skimmer with an ASM G-2 skimmer in a sump, and the reality was that there wasn't enough organic matter in the system to allow the larger skimmer to function properly. I would get dry foam in the neck of the skimmer, but there wasn't enough to push it over the lip and into the cup. What ended up happening was that I would raise the bubble level in the skimmer cup neck, and splashing/rupturing bubbles would splash saltwater into the collection cup and the salinity would drift over time if not adjusted. I ended up going back to the Aqua-C skimmer and got better results.

 

[Kattes]

I really doubt the possibility of overskimming. Sure it's possible for the skimmer to remove coral food and other things that are beneficial, but the skimmer itself limits so much. Perhaps some huge cone with a tiny riser pipe could maintain a foam head and skim ridiculous amounts off to the point where it would be counterproductive, but I don't really see any of the commercial designs available today doing that. So yes, my guess would definately be that if you have attach a ridiculously oversized skimmer to a tiny tank, the skimmers inability to funtion with the available load would keep it from overskimming. So if most skimmers are able to remove 30 or so percent of TOC available, I wouldn't worry about overskimming. Simply by looking the problem most ULNS keepers face, skimmer rarely has anything to do with either the problem or the solution.

But I would love to see what happens if someone built a gigantic custom skimmer to work with minimal load and tested what happens. Of course most small systems would crash due to salitiny changes way before the skimmer would actually cause serious problems, but provided that there was some computer controlled doser that dosed both SW and FW ATO ... And then it would become a question of whether the effects are actually caused by the continuous water change performed by the skimmer or the actual process of skimming.

 

[Sk8r]

Strong skimming helps sps, which mostly eat light. IMHO it's likely to be a negative for lps and softies, who such stuff from the water for a major portion of their food. I have a skimmer which works a few hours once a month if I jiggle it around. LPS grows like mad for me. Softies proliferate with NO skimmer at all.
Certain species of non-sps may benefit from a really good skimmer, in instances yet to be proved. But in general, my vote is no, where it regards the typical lps or softie coral.

 

[Reefin' Dude]

it all depends on the organisms wishing to be kept in the system. whether or not the organisms are looking for inorganic phosphates or organically bound phosphates.

SPS, you can not overskimm. they are not interested in inorganic phosphates, they are looking for organically bound phosphates, and if you supply this with the feedings, they will be happy campers. as you go up the trophic scale the more eutrophic the organism the less important the skimmer becomes. (though there still needs to be a mechanism for nutrient export that allows the desired trophic level to be sustained).

G~

 

[Michigan Mike]

I think the point is to get a skimmer that matches your needs of nutrient exportation.

You can have a SPS only (no fish) and do not see a reson to get a huge/oversized skimmer, but that's me. Take the same situation and add a bunch of fish...another story.

 

[biecacka]

Well said mike

Corey

 

[mandarinfanatic]

thanks guys this is a great help especially the comment that the skimmer should match need for nutrient export.

 

[saveafish]

I love striping the water. Like the set up I am doing now I a 75 W/40 breeder sump. I will be adding a 10-20g refuge later. I got a ASM-G4+ on it. We all usually dose enough or add enough what we do over skim we usually dose back. Though point given PROTEIN skimmer is designed to remove proteins. If it was a salt remover it would desalinate and probable be called a desal. There is good proteins too but that is usually put right back by the bio load. You can get very technical with it. Like LouH above he had troubles with foam head stability. The more proteins you extract the more the surface tension changes. Here is an example look at Beckett skimmers. They are strippers of proteins. But just touch the water or look at it funny and the foam head falls on them and takes hours to rebuild.

 

[ChadRaay86]

I run a 500 gallon rated skimmer on a 300 gallon DT and I notice it just won't skim if there isn't anything more for it to skim out. No negative effects for me thus far, although I feed heavy

 

[unze]

I doubt you can over skim, however getting a skimmer that is far too big might not be better as it will not skim to well as their will not be enough organics for it to work well.

 

[Timber77]

I would say 99.9% of us underskim if anything. if you have a skimmer thats got a wider neck you will get the dry stuff in the neck alot more than with a smaller neck skimmer on the same size tank (all other things being equal) if thats your problem you could try vodka dosing (or biopellets-zeovit - kinda all the same) that will increase the foam production as well as feed heavy.

I run a t5000 aquamedic 6 .5 foot tall 8 inch skimmer with OR3500 pump on a 125 gallon tank. its rated for 1000 gallons. Don't see alot of people with this skimmer on RC but its my favorite... I feed this tank very heavily (rods, rotifers, half the frozen section at the local chinese market, and always have sheets of nori for the tangs.... kinda a transition tank between quaranteen and going into my display tank..I have a few larger tangs that like to pick on the new guys so i tend to let them fatten up in this system first and its alot easier to check them for disease b4 going into the display tank.... 80-90 percent of the time it has a nice baseball sized foam ball in the top of the cup. Have never seen any evidence that you can overskim nutrients from saltwater with hobby grade equipment.

On my display tank (48x120x30)I run the same skimmer body with 2 OR 3500 pumps (manufacturer rates it as 1250 gallons) and dont really feel its being underskimmed at all. The cup on the big tank gets emptied every 2-3 days the smaller tank can go about double that between washing out the cup.

 

[Scotty1772]

I doubt it as well

 

[Celtic_Fox]

SPS, you can not overskimm. they are not interested in inorganic phosphates, they are looking for organically bound phosphates...G~

???

I've always read that skimmers remove organic compounds (and thus organic bound phosphate). Wouldn't that mean that skimmers are removing at least some of what SPS are looking for? (Hence one of the arguments for an algae scrubber...)

 

[mandarinfanatic]

turm off return pump for ten min when feeding tank

 

[mandarinfanatic]

ps there is enough phospate to go around in most tanks

 

[mc-cro]

In my experience, the skimmer will moderate itself. I have had the same skimmer on several different set ups, and if there is not enough to skim out, the skimmer just doesnt skim so well.

On the current tank, its bare bottom (almost) and I feed extremely heavy, and the same skimmer that barely pulled a light brown film is now pulling out dark green nasty thick skimmate. the type that leaves chunky bubbles on the outside of the neck.

I really dont think you can over skim. under feed yes, but not overskim.

 

[mandarinfanatic]

In my experience, the skimmer will moderate itself. I have had the same skimmer on several different set ups, and if there is not enough to skim out, the skimmer just doesnt skim so well.

On the current tank, its bare bottom (almost) and I feed extremely heavy, and the same skimmer that barely pulled a light brown film is now pulling out dark green nasty thick skimmate. the type that leaves chunky bubbles on the outside of the neck.

I really dont think you can over skim. under feed yes, but not overskim.

thanks for input

 

[elder luis]

if you have attach a ridiculously oversized skimmer to a tiny tank, the skimmers inability to funtion with the available load would keep it from overskimming.

Kattes,

Wich proportion do you call "ridiculously oversized skimmer"? How many times the tank volume?