Frustrating Protein Skimmer

[zeeter]

I'm fairly frustrated this morning. Wednesday night I went to bed after topping off the 75gl tank. Thursday morning I got up and the pumps were chugging up air because the skimmer had emptied everything down to the bottom. A few more minutes and the pumps would have been sucking up air.

I added enough to get me through the day as I didn't have time to get it to the proper salinity. Got home and did a proper top-off, then I turned the skimmer back on and watched it for a while. It seemed fine. I even cleaned the top chamber of it just to be sure. Sometimes they work a little bit too efficiently when they're dirty.

So about two hours later I found that my water line had fallen way down again. Skimmer was working overtime again.

So my question is this: is my skimmer working properly and legitimately getting rid of bad materials or is it malfunctioning? Typically it takes about a week to half-fill a 2 liter soda bottle and the water is black. This water was fairly clean.

It has done this before and then stopped after a few hours. I would make an adjustment to the air intake, but if it is working properly I think I should just let it run. Biggest problem is that I'm running out of RO water to top off with.

One thing I should point out is that my skimmer return feeds my refugium via a 3/4" tube. The return is really too much so I cut a couple of holes in the tubing to allow some water to empty out before getting into the refugium. I'm not sure if that would have anything to do with this or not. I got one fish recently, but it was only a royal gramma and I doubt that would put out this much extra waste.

 

[Sploke]

What kind of skimmer?

 

[zeeter]

I don't have the name of it handy. It's your standard skimmer - nothing fancy. Uses venturi.

 

[redfishblewfish]

Need a brand...and a picture of what you drilled with holes.

Some skimmers are very touchy. You turn them a fraction of a hair and they start spitting out everything. I'm surprised that you are getting black skimate with just one fish???

 

[zeeter]

Seriously - it's just your standard skimmer. It's worked fine on fully open for months, then just started to spew. I think it has something to do with the waterline of where I cut the hose. It's higher than the old output end was before the cut.

The new fish isn't the only fish in there, it's just the only thing different within the tank.

 

[Sploke]

There's no such thing as a "standard skimmer". There are probably 20 different companies that manufacture skimmers and they all have quite a range of models, and each one has its own advantages, disadvantages, and quirks that can cause problems.

A pic of how its situated in the tank would probably be most helpful.

 

[zeeter]

Not to be difficult, but when you picture a skimmer this is the one you picture. Input, output, waste line.

The problem was that the output was higher than it was originally due to the cut and it made the waterline within the skimmer rise. Consequently, the bubbling went higher and thus - skimmer on overdrive. It had nothing to do with the model - more of a physics thing that I didn't take into account.

 

[lanimret]

If I understand you correctly, yes, your modification is probably causing the problem.

The water level of the skimmer (and thereby the amount of skimmant it produced) is effected by both the water pressure from the input pump and the diameter of the output tube (back-pressure). So if your modification effects the back-pressure created in the return then you may be throwing your water level out of whack outside the range with which it was designed to be adjusted.



Then again, I really am not positive of what you were describing. If you post a picture we can probably help more.

 

[zeeter]

Thanks - no need. The problem is solved. Just needed to think it through. The waterline in the skimmer will always be at the height of the output. When I cut the line it was at a position higher than the original output so the waterline went up.

 

[redfishblewfish]

Zeeter, glad you figured out your skimmer and got it working right.

Just to clarify, saying you have a “standard” skimmer is like telling your mechanic, when you have a car issue, that it is a standard car, the kind you think of when you think of a car, you know, with four wheels. There is no such thing as a “standard” skimmer. You might want to investigate the brand you have just in case of future problems or if you need to buy parts.

Again, good job in your investigation in figuring out your own problem.