More on Sumps

In What is a Sump? I outlined the benefits of a sump based aquarium system. There are disadvantages as well, of course. The big one is water overflow.

With a sump, water over flows the show aquarium, drains through plumbing, and collects in a second aquarium (the sump). In order for the overflow to work, the overflow device has to sit some depth into the show tank. Even if the device only sits an inch into the water, that equates into some gallon amount that the siphon will continue to suck out if power is lost. Everybody has power outages, right? Obviously the amount of water lost will differ depending on the size of the overflow, how deep the overflow sits in the tank, and the siphon mechanism of the overflow.

The water that is drawn from the show tank will end up in the sump, and the water that is circulating in the plumbing will end up in the sump. All this extra water will raise the level of water in the sump. If the sump is too small, or too full, you have a potential disaster waiting to happen.

Any water that leaves your tank is a bad thing. The trick is to figure out the most full that the sump can be. (I will also have to figure out the least full the sump can be as well so that way the pump that pumps water from the sump back to the show tank does not burn up).

The other problem that can occur with a sump is water leakage. The more plumbing involved, the better the chance that a bad connection between two pieces of pipe will leak. (See note above about water leaving the tank).

This is how I plan to test my system to help ensure that I will not have any over flow problems. I am setting up a 29 gallon show tank and a 20 gallon sump. This will make sure that a few gallons overflow will be able to be collected in the sump. A 5 gallon sump may not have worked, and a 10 gallon may have been questionable. The 20gallon should be fine.

1. I am going to fill the show tank and place enough water in the sump to cover the pump for the system and the pump for the skimmer. THIS IS THE LOWEST LEVEL I WOULD EVER WANT. (They actually make little devices that alarm when the water level gets too low. I will probably be purchasing one).
   
2. After the water circulates for a while, and I check for leaks in the plumbing, I am going to turn off the pump. This will give me an idea of how much water will enter the system if/when I have a power outage.
   
3. Next I will add water until I get to the highest point I would ever desire my sump to be.
4. Now I will turn the pump back on. Naturally, the water level in the sump will decrease again.
5. Once the water level evens out, I will mark the water level in the tank. As long as I don't ever fill the sump beyond this mark, I should never have to worry about the sump overflowing due to a power failure.
   

Brilliant,. I think so.