My completely worthless DIY Skimmer

I'm n skimmer DIY'er. I have not yet tried to work much with acrylic and such. However, first thing tat stands out to me, is, shouldn't your venturi be on your recirc pump INTAKE rather than output? This way the impeller is what is "chopping" up the bubbles? Also, the water input I would not use my overflow. I would have it coming in to the skimmer and leaving from the bottom and I would use a seperate small powerhead to feed the skimmer from the sump.

LOL, I just noticed this thread is 4 pages long. I'm sure everything I just said was addressed several time. Oops.

 

Phish, Thanks for your thoughts. There wouldn't be much difference if I put the venturi on the intake, because lots of the bubbles that are produced by the venturi I used, are being sucked up again by the pump and therefore "chopped". I'm sending only half of my water from the overflow to the skimmer. The other half is being sent to the soon-to-be-refugium. I believe this is a good way of taking out nutrients directly form the overflow, but not all of them so the fuge gets some. Thanks again!

 

What is the flow rate through this skimmer and what size are the bubbles ? Bubble can continue to become coated with organic compounds for up to 12 minutes so the water flow through the type skimmer you built will do better with about a enough thru flow of 5 x's the tank size a day to start ..To feed a skimmer from a 1.inch drain to sump will overload them.. From the depth of the water bin the sump you have more flow in then pump out will the sump at that running level hold all the systems water if power goes off ? But the basic 4 rules with a skimmer is.
But to put it simply the rules are for a skimmer to work well are
Bubble size
Bubble size yea it does matter
Bubble quantity
Overall flow-thru rate
Quality of contact time
But the rules are not limited to just these or the whole story Back when we had to make our own I learned a few things and I Think with yours its the bubble dwell time in the reactor and to much flow you dial your skimmer to run the tank water through the skimmer body about 10 times a day it will do all you want. And a little slower would not hurt you'll have to play with the water volume to figure it out But a starting Min of 5 x to a max of 10 will do you the Salinity and Carbonates and calcium and temperature all play a roll in the bubbles size and quality It will take a week between water flow changes to get a good base line.

Flow rates are where many miss up with your type even more so , But even with a off the shelf skimmer Like a ETSS or Deltec Precision Marine all of them even from a Beckett to a mazzi venturi you dial them in to just pull enough air to get good fine bubbles and let them go .. Thats why some many with a Becket type even say their skimmer goes flat all the time LOL Surface tension is the problem and not enough dwell time in the skimmer you could cover all the skimmer ever made and they are all the same Bubble , air and dwell time and thru flows are the key's you Try slowing it up depending on the flows now and slow it up if necessary and see what happens

 

I don't think that the effect is as great at all. You definitely want to have the venturi on the intake, and do a mesh mod which is the easiest way to mod your pump to add bubbles and make them smaller/more numerous... Do a search on Enkamat and get some (split it with other as you won't need as much as what will come) the blast it with a heat gun and flatten it... Use the smallest zip ties you can get and wrap them around the impellar. (you can cut a notch to do this) make sure it doesn't rub anywhere and trim it if it does. You'll get tons of bubbles.

Also have you tried raising your water level?

 

Not only that but as an example, you may just get the same bubble 25 times,when you want to get 25 times the bubbles.

 

Not to mention that the pressure difference on have the venturi located on the output of the pump essentially makes you skimmer into a fancy Mazzei style high pressure skimmer. You will reduce the wattage of the pump also. This occurs from the air and water mixing in the volute and causing a state of cavitation. That then in turn causes the hydrodynamic friction around the impeller to decrease. All leading to a reduction on the motor!

If your using a needle wheel I would highly suggest giving Enkamat a try. Needlewheels have there purpose but that is best suited to a large pump that has to force air against a high head pressure...ie the Reeflo Orca or one of Spazz's monsters. Your starting to see a big push in the hobbiest market to switch to threadwheel design. Both ATI and Royal Exclusiv are switching over. Infact RE has a wicked titanium threadwheel.


Most of the design seems well thought out but the pump config is currently your limiting factor. Your not seeing the Air flow/ wattage numbers that you could get. I've tried both ways using a Dwyer RMA-22-SSV and a Kill-a-watt to test the effeciency numbers. I've never seen a pump that is running at peak in that configuration.

Hope this helps
Scott

 

Art the flow burst is being caused by the the dip in your hose from the overflow.

what is happening is Air is getting trapped at the inlet to your skimmer, and starts to cause a vacum and backs up your waterflow until there is enough pressure to push through, so if you are there when it happens you will see your hose shake and make a huge gurgling sound, i had this issue with my sump lines just raise up your hose in the middle so there isnt a dip in the middle it should solve this issue.

 

Thanks Hoverman, going to do it now!!

 

try this

DIY 4" Needle Wheel Skimmer

 

maybe you sould put the venturi on the intake insted of the output so it chops the air more