Where to drill my tank or overflows/return.

[Feelers]

Sorry if this has been posted about before, I found a post by chimera but the diagram wasnt working anymore,

Anyways............ my tank in 50 inches long x 23 high x 16 wide, and I want to get the tank drilled for overflow/return. Where and what should I drill, I figured I'd account for a flow of 10000lph to figure out the width of the holes so as not to underestimate.

Does the return from the sump get drilled 2 inches below the overflow? I think this is the case but why not at the same height?

If someone could post or link to a good schematic or draw a map with O marks the spot youd make my day

Also the guy at the glazier said that drilling would weaken the glass (I realise this) but shouldnt the tank be able to cope with this?

(there are 3 huge bracketts on this tank, outa the whole tank theres only 2 30cm x 40cm gaps to put anything in)

[cracker]

My advice would be to see other peoples tanks and follow the one you like best, before you start spending money on an expensive setup you may not want.

[chimera]

i would not drill for the return, you risk emptying to the bottom of the hole should your power go off. this could be quite a bit of water even at 1" below the water line. use plumbing up and over instead, that way you can alter later on if you want to add, say a sea swirl or some other rotating device. you can use non-return valves etc but they can get clogged and reduce flow. only drill for closed loops.

here is my return into the 1" sea swirl:

Also the guy at the glazier said that drilling would weaken the glass (I realise this) but shouldnt the tank be able to cope with this?

(there are 3 huge bracketts on this tank, outa the whole tank theres only 2 30cm x 40cm gaps to put anything in)

any drilling will weaken the glass, he's covering his arse by telling you that it will be strong enough so long as any drilling done is not too close to the edges.

for the overflow hole, drill it near the bottom, but as above, not too close for obvious reasons. then, add a durso standpipe to the mix to cut down overflow noise. heres the best pics I could find of my overflow:

[Feelers]

Thanks for the info and pics,

Sweet, well I wont drill for the return, altho I had acocunted for the difference, 5 gallons I think, but I spose its probably better to be able to use 5G more in the sump.

So if I have, say a spray bar as return, can I just drill in the top corner for the overflow?

chimera why is yours drilled with it at the bottom? Can't you just drill a hole at the top, with excess water flowing out it and down a pipe? I dont really follow whats happening in your overflow. Is the upsidedown "U" part of the tube where the water goes down the pipe and the bit at the top allow air to get in to let the water go down?

Do you think I should try and emulate your setup? I'd have to do some siliconing........hmmm

[suphew]

It's called a durso standpipe, it helps stop the noise of the water flowing down the overflow pipe. Well worth the trouble.

[HelifaxNZ]

Here is a couple of great websites to explain a few things...

http://www.melevsreef.com/what_sump.html

http://www.dursostandpipes.com/

Good luck.

[chimera]

say a spray bar as return

no dont use a spray bar in a saltwater tank, you may get salt creep and the holes will eventually clog up. better off having the water dumped into the tank (or if you want 'Y' it off two ways say at 45 degrees each if you are going to have an insane amount of return flow. then you could have the return in the middle dispersing flow nicely to both sides) dont forget if you have an external return pump, to add ball valves to each side so you can unplug easily for maintenance (not mandatory for a return, just easier)

can I just drill in the top corner for the overflow? chimera why is yours drilled with it at the bottom? Can't you just drill a hole at the top, with excess water flowing out it and down a pipe?

want to sleep at night?

I dont really follow whats happening in your overflow. Is the upsidedown "U" part of the tube where the water goes down the pipe and the bit at the top allow air to get in to let the water go down?

yes, pretty much. see the links above.

[Ira]

I use a spray bar, no trouble with salt creep or the holes clogging. Except for when a bag of carbon leaked all over the sump then I was clearing pieces of activated carbon out of the spray bar holes for a month. :evil: I keep the spray bar underwater though.