Odd observation - skimmer performance worse after adding outside air line...???

I was having low pH issues on my 210gal and so I decided to try the suggested run your skimmer air line through the wall and pull fresh outside air. Well this actually worked very well and my pH climbed to a healthy 8.0-8.2.

So anyway after getting my pH issue successfully fixed it seems my skimmer performance has dropped off. I used to always get a nice thick dark wet and dry skim before the change and now all I seem to get is the thin light pea colored skim.

I am using a SRO3000int skimmer and before the air line change I was running air through the silencer with both little black caps removed. Notice the little vertical cylinder with two smaller tubes coming out - that's the silencer for those of you not familiar with SRO skimmers.



So what I did was run a larger tube over the top of the main air line tube that goes to the skimmer pump and I ran that outside where it pulls fresh air. The tube I ran from the skimmer air line tube to the outside air was less than 3 ft long.So I would have to think that the skimmer is now able to pull more air now than before, plus its fresher air.

So any thoughts on why my skimmer performance would decrease?

Difference in air temperature being pulled in maybe? The inside air was 76F and the outside air has been in the mid 80's lately with heavy humidity here in GA.


Thanks

 

Is your venturi partially clogged? MIne starts to get clogged every few months, I run RO/DI water down the air line.

Can you adjust your water column?

Could it be less stuff to skim?

 

No clogs as I just set it up a week or so ago.

I pretty well have it adjusted right.


On another forum people thought that perhaps the larger airline might reduce air velocity somehow...? I don't know if I agree with that line of thinking or not, but I'm no physics expert either...

 

You would be surprised how restrictive hoses can be.This is mostly due to the turbulence crreated by them so it is conceivable to me that it could cause some restriction depending on the length of the tube and there relative size.
My first thought though is maybe your tank is clean. Did you have to change any of the air or water levels after making the change?

 

No, not the airline itself.

Take this bit off the skimmer that's circled in green and clean it. $20 says there's salt creep inside the tube right about where the red dot is at.

 

Good call.Always check the venturi first. 90 percent of the time this is the issue. I have to use a small screwdriver to remove the salt on mine.

 

Thanks I'll check for salt creep tonight.

 

Thanks Vinny! ;-)

 

No salt creep. I went ahead and cleaned the pump out and that didn't even make a difference....


Still really strange that it doesn't seem to be performing like it used to...

 

Give it time? After my WC's, the skimmer won't skim for a while either.