Need help with drains on 500 gallon tank...HELP!!!

[bballdad13]

I purchased a 500gallon (96"x40"x31") peninsula tank. The overflow is all at one end. Before I set this tank up I want to see if I can make it run smoothly or am I just better off buying a custom built. I only have 2 - 1" drains holes and no return holes in the overflow on this tank. I purchased a Reeflo Dart pump as a return pump and planned on coming over the top of the tank with the return. I plan on having 6 returns over the top. The question is will this be sufficient for primarily a fish only tank with a handful of LPS corals to give the tank additional movement. Should I just try to sell this tank and get a custom or can I get away with it? Thanks in advance for your help.

Rodney

 

[Alex T.]

Unfortunately 1" holes are not sufficient for that tank. Your return pump is WAY too powerful for the drains and will need to be throttled back almost 2/3 of the +3,000 gph that a dart puts out. I don't know why tank manufacturers insist on 1" inch drains.

If at all possible, I'd have the drains drilled to at least 1.5 inches...preferably 2 inches if possible. You'll never even pull over 500 gallons per hour out of each drain without serious siphon and risk of overflowing the tank in case it doesn't "catch" when the power comes back on after going out.

Read here.... http://www.wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm

Unfortunately, this means more problems than just flow and drain capacity. Your skimmer cannot properly "see" enough water to efficiently filter the tank. It will have bouts of having a foam tower, building up, foaming over and then collapsing again instead of steady and reliable performance. I had a friend with a Reeflo Dart pump over a year ago with this problem. Luckily for him he was using overflow boxes. When he ordered two new 1.5 inch overflow drain boxes I was able to help him plumb it in and let the Dart pump run almost at full capacity. To properly have that pump as the return pump you really need to consider 2 inch drains. I know this sucks to hear, but you'll be happier in the long run, and your tank will be much better filtered.

 

[Alex T.]

On a side note, those drains will barely give you 2 times per hour of turnover through the sump. For a fish only and some LPS I would personally shoot for at least 5 - 7 times per hour. You might always be fighting water quality issues. If the tank isn't tempered on the sides, you could always drill 2 two inch holes on the upper sides of the peninsula and have them drain to the sump much like fish stores do when they plumb all their livestock tanks together.

I probably wouldn't get rid of the tank. There's definitely a need for some modification, but this seems totally do-able.

 

[chewieee]

on my 300g i have a reeflow and iuse 2 2" drain lines, and it works quite well

 

[bballdad13]

I should have thought this through thoroughly before I purchased the tank. I am not sure if the back of the tank or bottom of the tank is tempered to possibly drill another drain...I can't imagine the side of the tank (facing the wall since this is a peninsula tank) is tempered but how do I tell?

The tank is far too heavy to move at this point so maybe I can have someone drill while it is sitting on the stand?