# Building a tank - Need Advice on Drilled Overflow for Sump



## davitt77 (Jan 16, 2010)

Let me preface this by saying that I'm no genius, but I'm fairly smart and I read a lot. I'm good with science and have kept many freshwater tanks in the past. I have read huge volumes on saltwater aquariums and believe I know what I'm getting into. Due to cost, I have decided to build my own tank, stand, and sump system for a FOWLR system. Oh yeah, and I'm very patient (a key, I believe to having a saltwater aquarium).

I was wondering about the best way to build in the overflow for a sump on a 65 (or so) gallon tank (24"x36"x18") that I'm making. I've priced the glass and looked at diy aquarium sites and articles. I've also looked at several calculators for the density of the glass, using tempered glass on the bottom, how to put it together and brace it across the top, etc.

From what I've read, it's much more desirable to build in an overflow system to a sump than to have an overhanging box. This makes sense to me, as it's a pain in the butt to build in (or expensive to buy) a syphon system that will restart in the event of a power outage. I will have my tank drilled. This is where my question arise.

1. If I have the bottom drilled, then I will go with 1/2" glass instead of 1/4" tempered which I currently plan to use. Drilling the bottom means I'll most likely have to run a system with a standpipe (I found killer instructions for a diy durso standpipe that won't act as a siphon in the event of the pump going off ). I have read that a potential problem with these is clogging. And it seems like more work than other options.

Option two seems appealing but maybe there are drawbacks I'm not thinking of. 

2. If I have the side drilled I can build in an overflow box that for sure won't flood if the pump stops working. Water will simply stop going into the overflow. I like this.

Question: Should I still have the bulkhead hole drilled in the bottom or can I put one (or more) in the side? Putting holes in the side would mean I could keep the 1/4" tempered glass for the bottom.

Question: If I put the holes in the side, where should I locate them, near the top or near the bottom? If I locate them near the top, then I need to use 3 pieces of glass to construct my overflow. If I put them near the bottom then I only need one piece of glass to create the overflow.

Question: How large should my built-in overflow box be? If I put the holes near the top, then that will limit size somewhat, as I do not want to have it jutting too far into the tank. If I put the holes near the bottom, then the built-in overflow box will measure roughly 24" x however far I put it from the edge of the tank (1", 2", ?) x 18". 

If folks advise that it's okay, more desirable, or even just acceptable to drill holes in the side rather than the bottom, then I have concerns about size of the box (how big should it be for a 65 gallon tank with a 20 gallon sump) and I'm I'm concerned that if I build the boxwith the holes at the bottom then it might be noisier than if I had a smaller box.

I really appreciate anyone's advice on this. I'm excited to do this but I want to do it right. My goal is to have the tank up and running with fish in it within 3 or 4 months.

Thank You,
Dave


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## magic_marty (Feb 3, 2007)

maybe consider making a overflow box that uses siphon to carry tank water to the sump..

Cheap Overflow - Nano-Reef.com Forums

i found this which might help..


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