Converting Euro-Reef Skimmer to a Recirculating Skimmer!

[Dudnerd]

Now correct me if I am out to lunch, but could I simply just drill two holes in the chamber, add a few stratigically placed plumbing parts and a pump.

I looked at a few of the RC series from Euro-Reef and it seems that is all they have done.

Any tips before I undertake this?

Thanx as always, Michael.

[Geoff]

why? would you want to do that to a skimmer?

i am still not seeing the usefullness in recirc a skimmer. to me it would make it less efficient. the increased circulation would speed up the water velocity in the skimmer causing your contact time with the bubbles to be diminished. this would mean that the smallest DOC's would not be removed from the water column.

it makes more sense to me to just put a bigger pump on the skimmer on the inlet side and call it good. that way your total water velocity in the skimmer has not changed that much. i am thinking that this is all marketing.

what you are saying is correct. all you need to do is add an inlet and an outlet to the skimmer with a pump. nothing more to it than that.

G~

[Dudnerd]

Agreed.... more or less. I see the sense in putting a larger pump, but I assume I need to be carefull there. The larger the pump, the more bubbles, but once again I have a faster turn over rate inside the chamber of the skimmer, which equals less contact time, no.

Sorry for repeating myself, but could you please explain to me in greater detail as to why you think that Recirc skimmers are less efficient, as I trust your opinion over most. For me I see the recirc pump on a skimmer reinjecting the skimmed water( which still contains some DOC's ) back into the the contact chamber for further skimming. While at the same time delivering a second stream of micro bubbles into the chamber without adding to the turn over rate of the chamber because the recirc pump also has a venturi on it.

Please dont take my posts as a sign of me knowing what I am talking about. I am just thinking with the keyboard.

Michael

[Geoff]

the problem is that the tiniest bubbles are not able to float to the surface, they keep getting shot around due to the extra flow created by the recirc pump.

the object is to keep the flow in a skimmer as slow as possible. that way tiny bubbles are able to find their way to the top to be removed by the skimmate.

if you were to increase the diameter of the reaction chamber to slow the total velocity of the water down than that would help, but then you would still be only processing the same amount of total water.

this is another thing i am not understanding about recircs. you are still processing the same amount of water. the only water going into the skimmer is what is being pushed in by the main pump. you are not processing any more water than it was originally. in fact it could be processing less depending on the flow dynamics in the chamber. it makes more sense to just increase the main pump. that way you are at least processing more total water.

you are correct that adding a bigger pump would also increase the velocity in the reaction chamber lowering the possible efficiency of the skimmer. this has a lot to do with the air delivery method of the skimmer. pressure driven skimmers just get more efficient the bigger the pump you put on them. the increase in head pressure increases the intake of air around the venturi/beckett/eductor thus making more violent, creating smaller bubbles. needle wheel skimmers will not do as well with increasing pump size. these are totally dependant on a low pressure venturi before the pump. you can not increase pressure before the pump before you start starving the pump and causing overheating problems.

as you can tell, not a big an of the needle wheel skimmer. they are just to finicky. this is why you see recircs on these skimmers only. just not needed on a properly designed pressure skimmer.

hopefully i did not bore you with all of this babble.

G~

[Dudnerd]

Pressure Skimmer?? By the way I have a Euro ES5-3. I think it has a sedra 3500. What can I do to make this more efficient?

Thanx Geoff, Michael.

[catalyst]

geoff: I'll second the question: can you give a brand-name example of a pressure skimmer, so we can get an idea of how it works?

thx

[Geoff]

pressure skimmers are those that use a venturi valve after the pump, needle wheel skimmers have a psuedo venturi before the pump.

Top Fathom, AquaC, MRC, Precision Marine, all use pressure to produce the bubbles for their skimmers. most of them are just different names for becketts.

if you see an air tube before the pump inlet than it will not be pressure driven.

did that answer your question?

G~

[catalyst]

Originally Posted by Geoff

did that answer your question?

yes, thank you

you might know the answer to this question:

I have yet to find, online or in print, a definitive and comparative listing of the different types of skimmer technologies - ie, venturi, counter-current, beckett, downdraft, etc ...

do you know of a book or a website, that itemizes and clarifies 'all that is skimmer' ?