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View Full Version : How does depth of water skimmers sit in effect skimmers?



Rhodes19
12-22-2010, 08:36 AM
Hi All,

Now that I have a big boy skimmer (SWC 200) for my 180, I have become aware that I don't know everything about skimmers. :D

What does the depth of water the skimmer sits in have to do with proper/optimal skimmer operations? And, how do you determine the optimal depth for the skimmer? I'm thinking the depth has to do with the water level in the chamber. Not so much to do with the power of the pump as it does with the water pressure on the out let (skimmer sits higher = less pressure, skimmer sits lower = more pressure). But if you can regulate the amount of water in the chamber by adjusting the out let tube/gate valve, does the depth the skimmer sit in really matter?

Any way, if anyone can explain it to me I would greatly appreciate it. Thanks.

Chris

mcoomer
12-22-2010, 09:19 AM
The depth of water affects the skimmer pumps ability to pull air in through the volute or venturi. If the skimmer is too deep the pump can't pull as much air in as it can if it's in shallow water. Less air means fewer bubbles/irregular sized bubbles which causes skimmer performance to suffer. Not sure what the effect would be if you had your skimmer in a very shallow sump other than the possibility of the pump creating a whirlpool and pulling less water.

Mike

Skimmy
12-22-2010, 10:46 AM
well, thats 90% correct... :)
it also depends upon the pump...
for instance the sicce psk 2500 pump on the mini s, extreme 200, and 180 cone, actually performs better with some back pressure.
it also has to do with the design of the skimmer body as well as the amount of water in the chamber the skimmer sits in creating back pressure on the outlet of the skimmer.

so, to answer your question what is the optimal depth? it changes for every skimmer/pump combo...
for your skimmer it's 9-10"

Rhodes19
12-22-2010, 03:22 PM
The depth of water affects the skimmer pumps ability to pull air in through the volute or venturi. If the skimmer is too deep the pump can't pull as much air in as it can if it's in shallow water. Less air means fewer bubbles/irregular sized bubbles which causes skimmer performance to suffer. Not sure what the effect would be if you had your skimmer in a very shallow sump other than the possibility of the pump creating a whirlpool and pulling less water.

Mike

Hi Mike,

Thanks, that makes sense. So basically, the water depth/pressure on the pump/air intake has an impact on bubble production and quality. So, in my case, 8-10" (manufacturer's recommendation) of water is the sweet spot for my skimmer and that's where I should get optimal bubble production. Thanks, that was an easier answer than I was expecting. :)

Rhodes19
12-22-2010, 03:31 PM
well, thats 90% correct... :)
it also depends upon the pump...
for instance the sicce psk 2500 pump on the mini s, extreme 200, and 180 cone, actually performs better with some back pressure.
it also has to do with the design of the skimmer body as well as the amount of water in the chamber the skimmer sits in creating back pressure on the outlet of the skimmer.

so, to answer your question what is the optimal depth? it changes for every skimmer/pump combo...
for your skimmer it's 9-10"

Hi Mark,

Thanks. I have mine sitting at 10" like you told me and its pulling out some nasty gunk. :D If I were to play with the depth the skimmer sits at what would I want to look for as indicators that the skimmer/bubble production is working well verses poorly? I'm thinking and increase or decrease in the number of bubbles and maybe bigger or smaller bubble sizes. I'm just curious, I like to know how things work. :)