Drilled overflow

[ShrimpFan]

Hey folks,
Ok, so I'm looking at installing a drilled overflow in my tank. However, I've looked at the options at glass-holes.com and would prefer a bottom drilled option as I'm trying to also allow the return to come through the bottom of the tank (I want nothing going on the outside of the tank what so ever). The problem I'm finding is in getting an overflow box to silicone in once the holes are drilled for a reasonable amount of money (so far I'm getting prices like $160 for just the bulkheads and box + $40 for the two drilled holes). I thought I had seen someone in the threads that did these sorts of things, so wanted to hit ya'll up while also searching the net for input.

Thanks
Aaron

[hobogato]

aquarium designs carries black acrylic overflow boxes that you can silicone in. even if they dont have one the right size, they can have dan make one the right size. be careful drilling the bottom of the tank, if any of the glass is tempered, it will be the bottom. you may want to contact the manufacturer to find out. i do know that if it is an oceanic tank, the bottom is likely tempered.

[Bill S]

Ace did my overflow - but he no longer does that. Because the box is under pressure, it usually sticks rather well to the glass.

I'd strongly suggest that you reconsider drilling the bottom, unless you know for sure that it's not tempered. Because it likely is.

[ShrimpFan]

Dang...I'm pretty sure it's an oceanic, and the bottom appears to be a diff type of glass than the sides, so I'm gambling the bottom is tempered and the sides are not. Well there goes that idea. Well, I guess I'ma gonna go with the glass-holes guys, and now I got Jason at Aquarium Designs thinking he may score one of their kits to check it out...:) Thanks for the input guys.

Aaron

[ErikH]

I would suggest a Calfo style overflow. Most of the unwanted proteins are within the top 2" of your water's surface. The calfo runs along the back, and stops just short enough to accomodate your returns on each end. With this style, the surface water is always flowing over it, instead of a corner of the entire depth of the water column. Thus you get more efficiency out of your skimmer, and refugium; the areas that process your waste water. You may want to go with 2, 1 1/2" holes for your drains. Then one of your drains could be clogged and the other could handle the excess created by the blockage. Just make sure your return is not faster than what 1, 1 1/2" hole can handle. That should be around 1400 gph or so.

[ShrimpFan]

I would think that could be controlled by using the return and any powerheads to agitate the surface of the water towards your overflow while getting oxygen into it. Also, I don't need 1400-1500 gph flow out of my tank into the sump imo, but if I'm wrong, please let me know. I'll be getting the necessary flow around the tank from powerheads using an 1200gph flow figure with 500-700 coming from the overflow from glass-holes.com and the rest from powerheads. Is this not a good way to do it, or is there better? I was told that should be sifficient, and provide plenty of waste filtering by using my algal refugium.

Aaron

[Bill S]

If it's an Oceanic, you likely have a tempered bottom. Mine is. Used to be, you could call them with the serial number of your tank and they would look it up for you.

I second Erik's recommendation on the Calfo. It's the single best thing I did with mine - eliminate the overflow and to to an 1800 gph calfo. Mine is in the end of the tank - since it's a see-thru tank.

[corruption]

+1 on the calfo -- the problem with just agitating the surface, is your unwanted proteins are going to be near the surface, collecting and 'bonding' before going into the overflow.. The surface agitation just disturbs this, and chops the proteins back into the water column. Also -- Erik wasnt suggesting running 1400gph through your sump, but instead making your outflow CAPABLE of larger flow... As he stated, clogs are a very real possibility, and you *need* to be always capable of handling the return flow... Doubling up on (larger) drains helps this, and also allows for further upgrades down the line..

-Justin

[ShrimpFan]

Hmm...ok, thanks for the food for thought. So from what I'm seeing thus far, the calfo is simply a style of overflow that goes mostly across the side you are draining from. So would the 1500gph box from glass-holes.com be a calfo since it's a 12" box on a 17" side? My tank is going to be see through as well, so the box is going on one of the ends like yours did bill.

Appreciate all the input guys, this is making alot of sense.

Aaron

[corruption]

On a side, you wont get as much surface skim ad the back, but otherwise dead on. You should have enough space on the sides to pull off 3/4" returns on either side of the overflow as well :)

[Bill S]

I put the calfo on one end, and my 18gph return on the other end. The entire surface sheet gets replaced every few seconds.

Make sure you have enough room between the calfo and the front and back to get a cleaner magnet in. I just "parked" my cleaner magnets at the calfo - and you don't even see it.

Yes, size your drains so that they can handle 200% of the return flow, AND make them redundant. In other words, 4x your expected return. As your tank ages, your flow will slow a little, and then a turbo snail will get caught!

[ShrimpFan]

Ok. Just bought the 1500gph glass-holes setup. I'll send pics once it's in...:)

[ShrimpFan]

Hey folks,
Just got the overflow in the mail, tank drilled, and installed it. I'm liking it so far. Take a look if you'd like...:)

4680
4681
4682

[corruption]

Looks great! I copied their silencing method for the overflow on my 75 (1.5" street elbows with a 1/4" airline in the back) -- works fantastically :)

What size tank is it -- 40 breeder?

-Justin

[hobogato]

good job, looks great!

[ShrimpFan]

It's actually a 60 oceanic that I vinyl died the trim on to make it black. Taking the week of next week to finally get it all setup, so we'll see how it turns out, but I can't wait to finally really dig into this thing...:)

[jesserettele]

How's everything coming? I am just now setting up a 75 that is drilled on the rear glass on each end with 1 3/4" holes and would like to do the similar drain set up. What size holes did you drill with that kit?

[Mr Cob]

yes, great job. looks nice. You'll be happy with it! :)

[ShrimpFan]

Thanks,
It's going well. Just posted a new thread with the new tank setup here. (http://www.maast.org/forums/showthread.php?p=723386#post723386)

Aaron