FranklinP":19644x5i said:
I am planning on sectioning off the corners of a 250G acrylic tank to create two overflows. I was going to seal them in with silicon sealant for aquariums. My other thought was just to have a 1.5" PVC SCH 40 stand pipe with a foam on the top. The pipe would be simpler but I have only seen this set up on bait tanks. Any thoughts would be apreciated. I bought the hole saw today, Made my own bulk head fittings from M/F adapters and a flat rubber gasket. Thanks. Frank
Ps: I posted in Newbee forum all tank info.
IMO the best "retro" overflow is based on both the standpipe and overflow principles.
Make a 5-sided overflow box out of whatever color you choose. Imagine an "island" type overflow (4 sides, fins on each) but this one has a bottom as well. Drill your bulkhead holes on the bottom of the tank and the bottom of the overflow box. Use a standpipe to connect the bulkead from the bottom tank to bulkhead on the bottom of overflow. If you locate the bulkhead holes correctly, you can snug it up to any tank wall you desire and seal with silicone if you wish.
Hope this makes sense, this type of box has a few things going for it.
* You can make the overflow box itself as tall as you'd like or as short as you like. Meaning if you want it to run the full height of the tank, you can, if you want to be small and in the corner, no sweat.
* You are not making any permanent changes to the tank so if it doesn't handle the flow you want, you can remove & replace it easily.
* Since you're not gluing anything to the tank, you can change it's location easily by simply plugging the bottom hole and drilling a new one someplace else.
* You can make it as big as needed to handle Durso type setups
* You do not have to worry about getting a water tight seal to the tank.
* If the tank has previously been filled, you don't have to worry about gluing to any warped tank walls.
* You get the convenience of standpipes with the saftety and flow rate of traditional overflow.
* If you want to drill in the back of the tank instead, just use the bulkhead with an ell.
* If you want to get creative with the overflow shape, fine, use tube if you wish, makes no difference.
The biggest advantage though IMO is that you don't *have* to rely on silicone at all for sealing anything. Though many folks have glued acrylic overflows to tanks, I rcommend against relying on it for structural purposes when sealing acrylic as most silicones don't stick to acrylic *that* well.
BTW, you guys are hysterical :lol:
HTH,
James