Adding Top Off To Sump

[cm11599ps]

I've got a Lifereef sump coming any day now but I have a few more questions before setting everything up. My tank is not drilled so I'm using a custom Lifereef overflow box.

1) To do water changes I'm guessing I'm going to have to put a hose in my tank to drain since I'm using an overflow. That's fine as I already have it anyway from my freshwater setup. I plan on having a separate container to hold my new salt mix and then use a pump to fill my tank again. How do I go about using my sump to fill my tank though? Do I close the ball valve on my return line reducing the flow back into the tank because the pump adding the new water won't be as powerful as my return pump? Should i just add the new water to my tank and then let gravity take it's course once the water level in my tank hits the overflow?

2) Evaporation. My return pump chamber has 2 lines. A higher line for water level and a lower line for "add water." Is that the only area in the sump where the water level would drop? If so, why?

Any further explanations of this would be awesome! Thanks!

[tkeracer619]

1. Just add water to the tank. When you have an overflow it does just that. Unless it gets clogged or it looses siphon it will drain all excess water to the sump.

2. That should be the only place. The sump has a baffle in it that will keep water at a certain height. The tanks overflow keeps the tank consistent and that baffle in the sump keeps it consistent. The only place to see how much water has evaporated is in the final chamber. This is where your auto top off goes if you choose to have one.