Island to Island overflow in 125

thegrimreefer · 01-01-2006, 05:40 PM

OK, so those of you who've been following the saga, know that I'm putting a 125 in wall, with small "fishie room" behind it.
Mine's an all-glass 125. Old, but unused, no center brace. No tempered glass, even in the bottom. Has a sticker that says "OK TO DRILL".
I like the idea of the through-the-back-of-the-tank external overflow boxes that those with acrylic tanks can do. No way I was going to try to put those holes/slots in the back of the tank glass.
I also like the coast-to-coast overflow idea, surface skimming across the length of the tank.
What I don't like, is taking up tank real estate wth large, bulky, unsightly overflow boxes, be they in the corners, in the middle, wherever.

Thus was born the compromise. Not coast to coast, but island to island, using two holes through the backwall.

Spazz fabricated the acrylic work for me, including making the external boxes twice, because I was negligent in my dimensions the first time.

Here's the internal piece. Long, but low profile, very unobtrusive in the tank

And glued into place.

To glue it in, I used a combination of epoxy and silicon, with the epoxy anchoring the ends and corners, and a point or two along the length. All surfaces were first cleaned with water and acetone.

thegrimreefer · 01-01-2006, 05:43 PM

The external boxes cover the back side of the holes. They're glued in with epoxy I previously tested with acrylic and glass, subjecting the test pieces to temps from 6 F to 150 F. Held tight as could be. I also applied a coat of Marine Goop to the outside of the joint. Goop stays a bit more flexible, so it'll make a good backup joint, but I doubt I'll need it.
The left one is drilled for a gravity feed into the protein skimmer.

carman34l · 01-01-2006, 05:45 PM

Very Nice!!!

thegrimreefer · 01-01-2006, 05:45 PM

A stockman style standpipe through the 1 1/2 inch bulkheads provides the drains.

So, that's THAT!

redwinger · 01-01-2006, 06:43 PM

That is really cool. Do you think the epoxy will be enough to support the water weight in the overflow boxes?

spazz · 01-01-2006, 06:59 PM

ok now that you have water running through the tank. is there alot of noise from the overflows? or is it quiet? how many gph are you running through it?

thegrimreefer · 01-01-2006, 07:08 PM

I'm not willing to TEST this theory, but I'd guess I couldn't grab that overflow and tear it off by hand on purpose. It's REALLY on there.

Quote:

Originally Posted by redwinger

That is really cool. Do you think the epoxy will be enough to support the water weight in the overflow boxes?

thegrimreefer · 01-01-2006, 07:11 PM

The overflows aren't very noisy at all. a little gurgling on the inside overflow, but I can do some things to quiet it. The majority of the noise is where the returns dump into the sump.

I can, and have, run the full output of the amp-master (3000?) through the main display alone. No trouble. In operation like now, however, that output is split between the tanks.

Quote:

Originally Posted by spazz

ok now that you have water running through the tank. is there alot of noise from the overflows? or is it quiet? how many gph are you running through it?

salty65gal · 01-01-2006, 08:17 PM

nice overflow!

Tutmos · 01-01-2006, 08:21 PM

I really like that overflow. Is there any reason you couldn't have just used bulkheads with fittings that run a tube straight to the sump instead of the external boxes? The main reason I ask is with a low return flow, Mag7, and a noisy HVAC hum 24/7 in my office I'm not concerned about a little water noise. I'm planning to have Superman come and drill my tank later this month when I move it and I haven't been too thrilled about using the big RR style internal boxes. Any reason I couldn't use the same internal box Spazz made for you and drill it for that and use bulkheads that just connect hoses down to the sump? I don't think I'm brave enough to do the bottom the way you did

Looks very nice.

Kevin

thegrimreefer · 01-01-2006, 08:39 PM

Two reasons I didn't do that.

I couldn't have my gravity fed skimmer that way, without some creative plumbing.
pushing 1200-1500 gph through each side of the overflow that way would have been TOO noisy.

Lower flows will still gurgle a lot, I think. You could use larger islands.. the internal boxes at the ends of the long raceway, and put elbows in them, and assemble the remainder of a durso style overflow off the outside end of the bulkhead. I thought about doing that for a long time, until my testing with adhesives turned up one that I was confident would hold the external boxes securely.
My main goal was for the overflow to be as "invisible" as possible.

Once I get a sheet of thin black acrylic onto the back of the tank, hiding the room behind and the outside overflows, etc, the internal piece will just fade into it. I hope. :-)

spazz · 01-01-2006, 10:55 PM

3000 gallons an hour! oops.... will the water level even reach to the top of the trim???? i didnt think it would flow that much water. its not going to be a problem is it???

David Grigor · 01-01-2006, 11:04 PM

Ampmaster is terrible under any head pressure. It won't be pushing near the max gph the pump is rated at, lucky to get 2000gph out of it as a return pump.

I also ran that as a return pump on the 300g, had I known actual wattage before I bought it I wouldn't have chose it. The rated 1 amp is a joke also, when running as a return pump was pushing 208w on my watt meter........

thegrimreefer · 01-01-2006, 11:42 PM

yeah, I dunno what the pump is putting out exactly.
I can put enough flow into it to make the water spill over the top edge of the raceway (on the that's slightly lower, due to the inaccuracy of the installer (me)). The water in the external overflow boxes never reaches the bottom of the trim, which is 2 inches "high".

HFG · 01-02-2006, 02:46 AM

Nice box!
Is there something on your system that is NOT crazy custom?\