Drilling a tank!!

[muck]

Im going to drill my tank for an overflow... and I have a few questions.
I am thinking of drilling 3 holes in the middle back bottom of the tank.

1. What is the minimum distance the holes should be spaced apart??

2. What size holes should I drill for the overflow?? There is to be a main line to sump and one backup.
(Just in case... :mrgreen: )

3. What kind of turnover ratio should I be trying to achieve for my 40Gal Tank??
Will probably go with a Mag Sumbmersible pump in the sump for now.
Would a Mag 9 be enough flow??

[Invigor]

3. What kind of turnover ratio should I be trying to achieve for my 40Gal Tank??
Will probably go with a Mag Sumbmersible pump in the sump for now.
Would a Mag 9 be enough flow??

I used a mag9.5 on my 48gal. nobody seemed to be bothered for it -- got some nice surface agitation with that much flow.

[mr_alberta]

Hey Ryan,

You need to figure out which pump you want and how high it will be from the sump to the tank. Then you can figure out the appropriate sized hole (though I think a 1" bulkhead = 1 3/4" hole would be good for you).

I also don't think I'd feel comfortable with my holes closer than 3" apart...but I'm a paranoid kinda guy :mrgreen:

Also, for turnover, you need to decide what type of corals and whatnot you plan to keep. If you are doing only SPS, they would need more flow than say, a tank full of LPS hammers and frogspawn.

[Richer]

I personally think that you should get as large as a pump as you can (within reason of course) for your tank and connect a ball valve to it. If you find that the flow is too much, you could always close the valve a bit. I was a bit paranoid when I plumbed a mag9.5 onto my 30 gallon (since I already had two MJ powerheads in there)... but it turns out I like the amount of flow going through my tank, so I've left the pump going full throttle. I've heard that one 1" drain should be enough to handle about 800gph of drainage. Two 1" drains should work well for a mag9.5... it gives you the extra drainage capacity incase one of the lines get partially plugged up. I know that in my tank, I can literally stick both my arms all the way into it, and the drains handle the extra flow without breaking a sweat.

I think Dez has a template made for drilling 1" holes... complete with spacings and stuff. At least, it looked like he had one when he drilled my tank (two holes for two drains in the middle back of the tank). Maybe see if you can borrow that from him?

-Richer