top off

[dermer]

so what is the best way to set up an auto top off on my main tank cheep i dont have a sump so it most go to the main tank dont worry about looks im good at hiding plumming and making it look nice i just have no idea how to set this up or what is needed to do it

 

[Johnbob]

The cheapest set up for top off I have seen is to have some container for your top off water that has an air pump line going in and a water line going out. Time how long it takes to deliver a certain volume of water from the time the pump is turned on until that volume is delivered taking into account head pressure to deliver into your display. Figure out your evaporation rate, then set the air pump up on a timer to deliver that amount of top off water or a little less on a daily basis. You will need to install check valves in your top off water delivery line that goes into the display.

 

[jimmyray]

That setup would need to be above the water level in the display, otherwise you'll siphon water out of the display, possibly flooding.

 

[Johnbob]

Jimmy, that is not true. If you will notice, I specifically stated that check valves will need to be installed in the water delivery line. Furthermore, if one places the end of the top off delivery line just above the full level of the display tank, there can be no siphoning from the display tank since the end of the line will not be immersed.