Skimmer water depth

bradbmbj · 12/06/2008, 09:31 AM

Hey everyone, I have been sitting here thinking about why does the depth of water affect Skimmer performance. The water height inside the skimmer body is set based on the riser and the pump has far more suction than the micro difference in pressure from a few inches of water depth pressure, what I mean is we all know deeper water equals more pressure but even a full 12 inchs of water only has .433 psi that will not be enough to force water in the pump. so what do you think?

noboddi · 12/06/2008, 10:44 AM

It makes a big difference. Whether the skimmer has six inches of water in it with the pump off or 12 inches, when the pump starts up and injects all the air and water matters a lot.

I think the point is not what the water pressure is, but how much water is in the skimmer at rest. Could be wrong, I don't know the physics involved just empirical experience.

Most skimmers are designed to work best in 6-8 inches of water. If you have more, put the skimmer on a stand.

bradbmbj · 12/06/2008, 04:26 PM

yeah thats just it, its not a pressure issue and the level in the skimmer is set according to the riser tube elevation so where does depth come in to play? I dont have a problem my depth is 8 inchs but this is just bugging me, it just really interests me to know how and why everything works the way it does in our systems

bradbmbj · 12/06/2008, 04:39 PM

The only thing I can think of is if you were to put a skimmer in deep water, and the water being injected is full of air there is a possibility the skimmer could begin to float, besides the pump weight holding it down it will have a tendency to lift.

noboddi · 12/06/2008, 04:48 PM

The skimmer loses buoyancy when it fills with water. What I think happens is that the point where the bubble column starts to form (sorry, don't know the technical terms) is higher when the level in the sump is higher. You will get wetter foam in my experience.

And the riser tube is not all that controls the water level in the skimmer. Water loves equilibrium. Put the skimmer in your sump, and the water level in the skimmer will match the level in the sump regardless of how you set the riser. It will go through the pump if it is off.

12/06/2008, 09:31 AM	#1
bradbmbj Registered Member Join Date: Sep 2003 Location: New Orleans Posts: 554	Skimmer water depth Hey everyone, I have been sitting here thinking about why does the depth of water affect Skimmer performance. The water height inside the skimmer body is set based on the riser and the pump has far more suction than the micro difference in pressure from a few inches of water depth pressure, what I mean is we all know deeper water equals more pressure but even a full 12 inchs of water only has .433 psi that will not be enough to force water in the pump. so what do you think?

12/06/2008, 10:44 AM	#2
noboddi Registered Member Join Date: Dec 2007 Posts: 813	It makes a big difference. Whether the skimmer has six inches of water in it with the pump off or 12 inches, when the pump starts up and injects all the air and water matters a lot. I think the point is not what the water pressure is, but how much water is in the skimmer at rest. Could be wrong, I don't know the physics involved just empirical experience. Most skimmers are designed to work best in 6-8 inches of water. If you have more, put the skimmer on a stand. __________________ Entia non sunt multiplicanda praeter necessitatem - William of Ockham Current Tank Info: 55 gallon (36x18x20), 40 gallon sump, 25 gallon refugium, TEK 6x39w fixture, Osmolator, Kalk Reactor, Vortech MP20, 2 Koralia 3s on controller, Acropora, Anthelia, Montipora, Starry Blenny, Yellow Watchman, Rainford Goby, Tiger Gobies

12/06/2008, 04:48 PM	#5
noboddi Registered Member Join Date: Dec 2007 Posts: 813	The skimmer loses buoyancy when it fills with water. What I think happens is that the point where the bubble column starts to form (sorry, don't know the technical terms) is higher when the level in the sump is higher. You will get wetter foam in my experience. And the riser tube is not all that controls the water level in the skimmer. Water loves equilibrium. Put the skimmer in your sump, and the water level in the skimmer will match the level in the sump regardless of how you set the riser. It will go through the pump if it is off. __________________ Entia non sunt multiplicanda praeter necessitatem - William of Ockham Current Tank Info: 55 gallon (36x18x20), 40 gallon sump, 25 gallon refugium, TEK 6x39w fixture, Osmolator, Kalk Reactor, Vortech MP20, 2 Koralia 3s on controller, Acropora, Anthelia, Montipora, Starry Blenny, Yellow Watchman, Rainford Goby, Tiger Gobies

12/06/2008, 04:26 PM	#3
bradbmbj Registered Member Join Date: Sep 2003 Location: New Orleans Posts: 554	yeah thats just it, its not a pressure issue and the level in the skimmer is set according to the riser tube elevation so where does depth come in to play? I dont have a problem my depth is 8 inchs but this is just bugging me, it just really interests me to know how and why everything works the way it does in our systems

12/06/2008, 04:39 PM	#4
bradbmbj Registered Member Join Date: Sep 2003 Location: New Orleans Posts: 554	The only thing I can think of is if you were to put a skimmer in deep water, and the water being injected is full of air there is a possibility the skimmer could begin to float, besides the pump weight holding it down it will have a tendency to lift.