how many times a hour should the water go through the sump?

[mr.wilson]

I can only lead a horse to water, the rest is out of my hands. This is the last time I answer this question, as there is nothing ambiguous in my responses thus far.

The original question was "just wondering how many times an hour should the tank water go through the sump? 1? 5? 10?".

Before that question can be answered we must first establish why you are using a sump? The answer to that question is the sump is used to house filtration devices so we don't have them hanging on the back of the tank and to a certain extent, to improve efficiency of these filters.

The next question is how much water do these devices require? The answer is whatever the highest demand is of any one particular device you are using. If you have a rapid sand filter that runs on a 1 HP pump, then you should run about 6000 GPH through your sump. If you are using a protein skimmer and it has the highest demand for feed water, then you need to establish how much water it has flowing through it. This number is likely to be 450 GPH, depending on the skimmer design. So in this case the answer to your question is your flow rate through the sump should be 450 GPH, regardless of the size of your tank.

If you are not concerned about the efficiency of your filtration devices, noise, operational cost, plumbing, saltcreep, water quality, temperature, display surface skimming, or initial equipment cost then pick a random number and multiply it by the size of your tank. Then place your protein skimmer in your sump and allow it to randomly draw in water and return it in the same compartment.