Water Physics Question...

[tamz273]

Hey guys, I have a question for you experts!
I have a sump running with an overflow box.. The overflow is almost full, and the sump water level is below what I would like it to be...

If I add water to the sump, it goes up to the tank and the water level in the sump increases proportionally with the tank level...

What should I do in order to raise the sump water level without changing the tank water level? I was thinking of putting a valve on the return pump's output, so that I can close it off a little bit... But wont that cause the water level in the tank to CONSTANTLY drop? and eventually overflow the sump...?

 

[Amphiprion]

Once the effluent from the return pump and the siphoning action from the overflow balance, simply adding a bit more water to the sump should raise its water level. There is a proportional work load that decreases with a higher water level, but not enough that it would negate that.

 

[tamz273]

That's what I was thinking too, but whenever I add water to the sump, it seems to simply pump into the tank and cause the tanks water level to rise...

Im using a cpr overflow, and that seems to be constantly full, unlike its "meant" to be working... Its supposed to look like a waterfall, instead the water level reaches the level of the rim and it just looks like a full container of water (but it is still overflowing water to the sump)...

What should I do?

 

[sundevil_brian]

you've reached equilibrium between your pump and overflow, so the distance from the top of the water in your sump to the top of the water in the tank will remain constant no matter the height of water in the sump. so if the sump water height raises 1" the tank water height raises 1" so the distance between will be the same as before. (you already figured that out)
To alleviate this problem you need to restrict your pump or add another overflow. the cheaper of the two options is restricting the pump. simply place a ball valve after the pump (never before it!) and restrict it till you get the waterfall effect you mentioned in your overflow.

 

[tamz273]

oh alright... funny thing is, it was running perfectly fine before a water change i did... right after the water change, this problem decided to happen!! Any way around it or is this the only solution? (Ball Valve)

 

[snailrider]

Something sounds wrong, with your setup or something. If your tank has not overflowed onto the floor, your siphon is working. Restricting the pump output is not the way.

On the outside of the tank, you may have to lower that resevior to lower the main tank level.

Please supply a few pictures of our overflow setup


Or you may just need a larger diameter u pipe

 

[snailrider]

oh alright... funny thing is, it was running perfectly fine before a water change i did... right after the water change, this problem decided to happen!! Any way around it or is this the only solution? (Ball Valve)

Then you got an air bubble in the siphon tube

 

[tamz273]

so i should suck it out and close the siphone again? ill try that right away actually... will post in 3 minz...

 

[tamz273]

just restarted the siphone (let air fill it up till it stopped and then sucked the air back out) and its sitll the same problem... the overflow box is filling up almost to the rim...

 

[tamz273]

actually its settling back down... not sure if theres an air leak or if its working properly.. its constantly going down at a VERY slow rate... it may have stopped now... should i try topping off the sump? or will this cause the tank water level to rise too?