Wierd water level issue
 

Not sure where to post this one but I noticed something strange about my water level. When I feed Mysis my watere levels raises about .75 inches in the tank. Sump level drops accordingly and my skimmer barely creates any foam! Everything returns to normal about an hour later so its no a big deal but why does this happen? Only after feeding mysis, no other kind of food.

Is the mysis partially blocking the intake to your overflow drainpipe?

reply
 

No, its not big enough. I have a 1.5 inch overflow and bulkhead to a 2 inch drian pipe.

Well, mysis is fairly oily and shuts down my skimmers for a while. I assume the lack of foam production puts less back pressure on the pump feeding the skimmer, thus the water level rises in the skimmer, and correspondingly, comes out of the tank. When the foam production begins again, it puts a little back pressure back on the pump, the water level goes back to normal and thus the level restores in the tank (notwithstanding any losses to evaporation, or initial foam spillover into the collection cup, or water put back into the tank during the slightly low period by a float valve or float switch and so on).

Thats what I was originally thinking as well but, he's saying the levels go the other way though Tony... :confused:

Well maybe it goes the other way then, ie., the skimmer has less water in it. Work with me here! :razz:

:mrgreen:

No, Tony's right. Skimmer shuts down, water from skimmer now goes to tank. As skimmer returns to normal and fills with water again, tank level goes down

Thats a lot of water to be only from the skimmer though.. :eek:

3/4" in a 65 Gallon tank guessing its 36x20ish.
Thats at least 2.3 gallons change in the skimmer..?? :eek:

The only other thing I can think of is that somehow the fluctuation in the sump level changes the back pressure on the overflow somehow, thereby affecting how it's operating. However, that said, this might only make sense if 1) the outlet of the overflow is submerged (which I don't know if it is or isn't) and 2) the water level RISES in the sump, thereby putting more backpressure on the overflow. A level DROP would theoretically decrease the backpressure. So... OK I'm at loss now. Maybe if I saw the phenomenon in person I could observe other variables but using my imagination, I've hit the wall here. :lol: