2 skimmers for our reef tank

[DeepBlue]

I have seen to many tanks in RC running with 2 skimmers...wondering how much more efficient it will be? I know the amount of skimmate will be different as one will tend to skim out more than the other.

Other Pros and Cons?

Currently running a RM mini beckett....I am contempting either to run an additional needlewheel (possibly H&S) ...

Beckett for volume and needlewheel for more thorough skimming....hmmm...imagine the water will be filled pack with oxygen

So far, I only know Roidan has tried running a H&S(needlewheel) with an Aqua C EV series skimmer(Spray Injection).

attached a pic from RC (2 euro reef needlewheel)

[AlfaRomeo]

DB, from what I understand , if you are running 2 different types/models of skimmers , eventually the more efficient skimmer will shut down the other. This is of course only true if you are not constantly feeding and that your total bioload is relatively light.

Example:

Skimmer A can clean up to 90%

Skimmer B can clean up to 95%

If the tank waters are at 85% cleanliness, both skimmer will still be pulling out junk.

However when the water is at 90% and above, Skimmer A will shut down as the water is too clean for it to pull out anything. Skimmer B will continue to cleanse the water up till 95%.

if we continually feed the tank, the water quality will drop again to below 90% and both skimmers will pull out skimmate again.

In a SPS-tank, we are trying for sustained water quality and thus should not be feeding the tank often to drop the quality too much.

IMHO, Get a properly rated or slightly overrated skimmer which can do 95% cleansing and you are set. Another option is to get 2 sets of the same model so they performance will be the same, the trick then is to tune the skimmers to pull out eaxctly the same quality skimmate which is quite a challenege.

What do you think of the logic above?

[weisoon]

Even 2 same skimmer will not perform the same rate due to:

1. In recirculating neddle wheel skimmers, the input flow from pump, how do you control same volume of water going into the 2 skimmers? Install a flow meter? Too expensive!

2. The rate at which the skimmer gets 'dirty and slimed' is different so the performance will end up different.

Better bite the bullet and get a overrated skimmer for the system for the super clean water then endup spend more money to buy RowaPhos and etc. The skimmer is the lifeline of the full system.

The only reason I can think of RC reefers uses 2 skimmer is 'backup', just incase 1 of them breakdown and you still have one to skim the system till help comes along.

my 2 sents

[Joe_P]

Rate a skimmer based on the volume of a reef.

As long as the volume running thru the skimmer is many times that of volume in the reef, you should be able to maintain rather good water quality. of course taking into factors like bubble intensity, water/bubbles reaction time etc. and of great importance, the water exhange rate between main reef and sump. (if skimmer has water flow channeled from sump).

Needle wheels are good at bubble intensity but do consider the water flow thruput into the skimmer... remember, the needlewheel itself alone would restrict substantial water flow.

I can only see the reason that 2 skimmers are employed on a reef is the amount of water that needs to be channeled into them to maintain proper water conditions.

No standards as to how much thru put here but I reckon the more the merrier ... hehe

IMO, Fire up your current unit with a MD 55 and you should be able to accomplish the above.

[strat]

Hmm...I have a thought here.

For needle-wheel skimmers, is it effeicent to put 2 needle wheel pumps to the input of the skimmer?

[lightningstrike]

Hmm...I have a thought here.

For needle-wheel skimmers, is it effeicent to put 2 needle wheel pumps to the input of the skimmer?

similar to the higher range deltec skimmers. 1 skimmer body wif 2/3/4/5/6 needlewheel inputs and pumps. 1 feed pump. my opinion will be the same as that of weisoon. IME, previously, i hv tried running 2 HOT skimmers in my tank. a prizm and a Aqua C Remora. 1 seems to outdo the other most of the time. finally, once and for all, i decided to replace both HOT skimmers wif a H&S needlewheel. it does a better job than having 2 HOT skimmers.

my 2 cents.

[strat]

similar to the higher range deltec skimmers. 1 skimmer body wif 2/3/4/5/6 needlewheel inputs and pumps. 1 feed pump. my opinion will be the same as that of weisoon. IME, previously, i hv tried running 2 HOT skimmers in my tank. a prizm and a Aqua C Remora. 1 seems to outdo the other most of the time. finally, once and for all, i decided to replace both HOT skimmers wif a H&S needlewheel. it does a better job than having 2 HOT skimmers.

my 2 cents.

Thanks..

thinking of adding another needlewheel pump to my skimmer.

wonder if like that can become deltec-wannabe skimmer...

[RAV-65]

I once had 2 Weipro 2012 running side by side, it turned out that one shut down the performance of the other, only one skimmed and the other one was a passenger...

Anyway, given the cost of running the 2nd skimmer, I rather use the $$$ to buy a pump or something to improve the water exchange rate between the main tank and the sump, the idea is to move the higher DOC water in the main tank into the sump where's there cleaner water to be skimmed and the cleaner water in the sump to be more rapidly delivered to the maintank, this can also improve the amount of current in the main...

Juz my $0.02...

[AlfaRomeo]

one skimmer will difinately out perform they other...but if i place a less efficient skimmer before a more efficient skimmer....some DOC will be skimmed out by the lesser efficient skimmer so by the time the more efficient skimmer "reskim" the water...there will be less DOC...so by then the more efficient skimmer will be performing below expectations also...but if put side by side...this will not happen...so if two skimmer are beside each other...will it be more efficient as more DOC can be skimmed out within a shorter period?

so have two skimmers is it the same as having more bubbles and longer reaction time?

Bro. your theory will only work when the cleanliness is still within the threshold of both skimmers.. pls refer to my example. once the water is above the threshold of anyone of the skimmers, it will be shut down no matter where the skimmer is (before,after,ontop, parallel). it no longer matters...

[RAV-65]

Bro. your theory will only work when the cleanliness is still within the threshold of both skimmers.. pls refer to my example. once the water is above the threshold of anyone of the skimmers, it will be shut down no matter where the skimmer is (before,after,ontop, parallel). it no longer matters...

IMHO, it also depends on the proficiency of the skimmer, if the skimmer not good enough, it will stop skimming ( when using two skimmers ) very very soon!

[AlfaRomeo]

I can only see the reason that 2 skimmers are employed on a reef is the amount of water that needs to be channeled into them to maintain proper water conditions.

Get 1 skimmer that can handle the tank volume and this is no longer needed. Its only necessary when 1 skimmer cannot sustain the demanded water quality.

It would be rather silly to use 2 skimmers if 1 skimmer is able to maintain the high quality water. Pls refer to weisoon and my post. It explains how it works logically (I think)

[AlfaRomeo]

Needle wheels are good at bubble intensity but do consider the water flow thruput into the skimmer... remember, the needlewheel itself alone would restrict substantial water flow.

Its correct and relevant only when the feed pump into the skimmer is also the pump generating the bubbles.

No longer true in the newer generation recirculating neddlewheels.

Due to:

1) Dedicated feed pump whose main purpose is to deliver tank/sump water into the skimmer for processing at the given rating. Pressure rated pump not needed.

2) Recirculating pumps used to mix air and water in excess of the flowthru rate of the skimmers

thus:

A given volume of water flowing thru the skimmer would be processed multiple times before being exited back to the sump.

[DeepBlue]

good info. Thanks for the insight. It just occured to me when I was surfing RC sites....these guys will use multiple CRs and skimmers.

CRs, I understand because of their sps demands. I am just exploring the possibilities....

spending the $$$ on a very good pump may seem to be an attractive solution...but recurring cost from the electricity just makes these pressurated pumps less attractive to me

[AlfaRomeo]

Check this out. Let the truth be unveiled:

http://reefcentral.com/forums/showthread.p...threadid=477208