Water Change and Sump

[keisersosei]

This will be my first water change with a sump and it is something I haven't thought about. Where do most people change the water when they have a small sump setup? I cannot take it all out of the sump since there are only several gallons, and only a gallon or two above the return pump. So, how is it usually done?

 

[keisersosei]

I know it doesn't matter as far as the actual water goes. But if I take it from the tank then it will just cause the sump's level to decrease, right? The water level should always stay at the lip of the overflow box. This, as I understand it, is one of the benefits of a sump: as evaporation occurs the sump level drops, not the tank.

 

[sal t. nutz]

Take the water from the main tank, but turn off your return pump while doing the change. Then when you add water back, add it to the sump, not the main tank. Turn the return pump back on and slowly add the new water to the sump, theis will make the adjustment in the main tank slow, in case there is a slight salinity or temp difference. Once the return pump fills the main tank back up to the overflow, the whole system will start itself again.

 

[jonthefb]

i think salty hit it right on the nose!
good luck
jon

 

[keisersosei]

And there will be no need to restart the siphon on the overflow?

 

[sal t. nutz]

If it is a good quality overflow box, it should never break siphon. As a matter of fact, I don't think there are any overflow boxes that break siphon from waterflow loss, unless it is homemade.

 

[worm]

Salt T Nutz (good name by the way) hit it on the head. The syphon will not break because the water is "even" on both sides of the syphon box. Once you start filling the sump with new water, then turn your sump pump on, the water will rise in the main tank filling the side of the syphon. More water in that box will cause the syphon to begin again, thus your system running back to normal.
I have a 10gal tank under my 55gal show tank. The way Salt T described how to change water is exactly how I do mine. One detail is that I have a line marked across the sump tank to maintain a consistent lvl between water changes....
Good Luck!

 

[keisersosei]

I see. And this will hold true after a power outage when the electricity comes back on, right? I also have a marking to let me know where 10 gallons is on the main tank. I am getting out the Sharpee to draw on the sump right now. Thanks.

 

[worm]

now power outages may be different. you see, depending on how high you sump pump has to deliver the water to your main tank is the question. if your pump should loss power, a reverse flow will happen because the rotor in the pump will actually begin to turn the opposite way because of the weight of the water in the tubing. If this happens, it will fill you sump until the end of that tubing (the one in your main tank) reaches air to stop the rotor from turning. What I did to eliminate this problem is installed a "check" valve in the line going to my main tank. A check valve is simple a valve that allows flow in only one direction. If flow would try and go the other way, it would "check" closed. When doing this, make sure the line going to the main tank from the sump pump is achored well. The weight of the water left in the line could cause it to fall out the main tank and onto the floor, resulting in problem #2. trying to explain all of this to the wife
HTH

 

[keisersosei]

I will have to put in a check valve, then. This exact thing happened when I first turned the pump on. It wasn't working properly so I unplugged the pump. You guess it: about 6 gallons of water all over the floor. I did cut my piping going into the tank so that it barely hangs below the water line, so there should be enough room in the sump to hold any water that decides to take a trip down a one-way PVC.

 

[slothy]

poke a little hole or holes in the return line that sits in the tank, so i will siphon air if it goes out