Skimmer Help?

[Waterboy]

I bought a LifeReef Skimmer(VS2-24H model). I am having problems getting it to pull out some gunk. What it pulls out is looking like light beer...I want to see some Guiness looking stuff come out. I have even had it set up at a friends house, curing some dirty stinky live rock. It still looked like light beer. We put on one of his cheaper bak-pak skimmers on the live rock tank. It was pulling out some nasty looking stuff.
Any ideas or suggestions?

 

[mojoreef]

Is that skimmer in air stone or a venturi style??
Either way it sounds like it's just skimming a little wet. Try turning the air down a little bit and see what happens.


Mike

 

[Waterboy]

It is a venturi style.
How would I adjust the air flow? Go buy a air valve to add to the air line?
Thanks for taking the time to help the newb out.

 

[Haole]

Yep, a valve on the air line is how you would do it but actually you need to get a needle type valve rather than a cheapy air line shut off valve that you see at your lfs. You’ll get a better range of adjustment from a precision needle valve. I picked this tip up from Anthony Calfo.

Here’s what I’m talking about and where you can get one online.
http://www.marinedepot.com/md_viewItem.asp?idproduct=CO3151

Another place that you can try is a local welding supply store but I’m not sure if it would be any cheaper.

Another thing you might try is lowering the water level in the contact chamber if you can.
hth

 

[dnjan]

It is actually better to adjust venturi-driven skimmers by adjusting the water flow. Best is with a gate valve on the line between the pump and the skimmer.

Skimmer efficiency is affected by the air-water contact time. You skimmer is skimming wet because there is too much air (as already pointed out). If you reduce the water-flow rate, you will decrease the amount of air pulled in, but also increase the air-water contact time.

If, instead, you just reduce the air flow, you won't be increasing the contact time, so your skimmer won't be performing as well as it should (could).

 

[liveforphysics]

Could you tell me what your reason for not likeing the pale skimmate is? Have you checked what happens if you leave the pale skimmate in a warm place to evaporate for a while? Does it turn into even uglier looking skimmate?

 

[Reefdaddy1]

Actually the Venturi types do better with a valve on the outflow ppart of the skimmer. Foam Head adjustment is easier to adjust from that point without affecting the contact time at all or affecting alot. Sounds like maybe a wider outlet tube might be in order. But I would think there is one already on it.
If there is, Adjust the valve on the return to where the foam head is about 1/4 inch below the cup. This will increase your contact time give you a dryer skimmate.

 

[Waterboy]

I do have a valve on the out flow. My outlet tube is a inch in diamater. I have set it up where about a 1/2 a cup is collected in a day. Still it looks real light. I think I can get find another valve at work along with mabe a needle air valve.
Thanks for all of your replys. Keep them coming. I am taking all of them in. I wish someone had the same skimmer, with some info.

 

[liveforphysics]

Now, once again, when you say it looks very light, can you elaborate on why this concerns you?

 

[mojoreef]

They you can use a gate valve between the pump and the skimmer no problem. It will make the adjusting or dialing in a little tougher as you are playing with both water and air at the same time, either way is good.

Luke
if you have a very light-colored skimmate it's showing you that you are pulling out too much water in ratio to the amount of proteins you're trying to remove. The end result compared to a dryer skimmate is probably the same but now you have to replace more water. Also if it's run that wet if there is an event that makes the skimmer go crazy you will pull out a ton of water, also when it is to wet you pull out more living organics.


Mike

 

[liveforphysics]

Thanks Mojo, I wondered if it was simply a matter of wasteing water, thanks for clearing that up for me. It seemed like the light colored skimmate would be removing more "bad" things, espically in a venturi/becket type application, so I didnt know why he didnt like it. But I can totally understand not wanting to waste the water.

 

[dnjan]

I don't know about beckets, but for a venturi skimmer, a really light-coloured skimmate generally indicates that less bad stuff is being removed.

While the organics generally "adhere" to the bubble surface, there will also be excess water on the bubbles. This excess water drains off in the foam column. When the skimmer is adjusted to produce a shorter foam column (or the foam is produced too rapidly to permit adequate drainage), you get less drainage of the excess water and a lighter-coloured skimmate.

Unfortunately, with venturi-driven skimmers, a short foam column (and/or excessive foam production) and short bubble-water contact time are generally associated (together) with above-optimal water flow through the skimmer.