Designing a sump

[phoenixb]

im designing a sump for a 150ltr reef tank and im needing a bit of 'help' with a few things -

the sump is a 51x25.5x26 ex. tropical tank

im thinking - remove the top bracings and resilicone.

im probably going to use either a 1500ltr/h return pump or a 1800ltr/h

im going to have just a hole at the back of the tank as the overflow (bulkhead i think its called)

im thinking il have 3 chambers - skimmer, small refugium and a return pump chamber.

these are my MAIN questions:

how big does the overflow hole have to be?

what are the 'variables' when deciding what water level to have in the sump?

could i use a rubber tubing back to the tank instead of rigid pvc?

do i need bracings, if so could i use perspect ones and put them above the chamber dividers instead of on the sides?

thanks.

[the-obstacle]

answers

1) big enough to handle the overflow caused by the output of your return pump or to put it another way big enough to handle the return flow of the pump and a bit more for safety's sake. If you're getting it drilled I'd suggest making 2 holes and setting up a herbie style overflow - more redundancy.

2) when the water flows over the sides you've got too much water in the sump. To be honest the more water you can have in the sump the more water you've got in the system which will make for stable parameters. Set the sump water level so that when you turn the power off and the water overflows from the tank to the sump it doesn't overflow the sump.

3) rubber tubing is fine - most pumps use rubber hosing instead of solid PVC. PVC is cheaper in general.

4) if you've using glass to create dividers you shouldn't need bracing.

[phoenixb]

thanks.

when you say "herbie style" does that mean the two holes have pvc that joins them half way down the back of the tank or - like 2 hole with 2 seperate pipes going down into the sump

[the-obstacle]

thanks.

when you say "herbie style" does that mean the two holes have pvc that joins them half way down the back of the tank or - like 2 hole with 2 seperate pipes going down into the sump

2 separate pipes running to the sump. search google for herbie style overflow system it'll explain it all. It gives a quieter overflow and allows for a backup if the main overflow gets blocked by anything.