Best way to secure baffles in DIY sump made out of old tank?

[dirtyclownfish]

Hello all DIYers, I was wondering what the best way to secure acrylic baffles to a sump made out of an old glass tank? I was just having some concerns about the silicone only bonding to the glass and not the acrylic. From previous experiences, I have learned that silicone does not adhere to some plastic polymers well.

[asm481]

glass tank is best with glass baffles. Some get away wit acrylic but use a ton of silicone to trap it. And don't have the acrylic fit tight, it expands with warm water and may crack the glass.

[Willistein]

Acrylic should be fine, but if you can cut glass, that would be better. I'll second the recommedation not to have acrylic fit too tightly; I actually had a tank crack when a snug piece of acrylic expanded slightly.

[rickh]

Acrylic works fine with silicone. I rough up the edge and about 1/2" of the surface where the baffle meets the glass. If you are careful it can look very neat. A friend cut the h@ll out his hand with a glass baffle. R

[rsw686]

My acrylic baffles are secured with silicon to a glass tank. It works fine. Yes silicon doesn't bond to acrylic that well. However as long as you put a nice bead on either side of the baffle it will act as a wall and keep the baffles in place.

[dirtyclownfish]

Thanks everybody, just before I buy a sump-tank, what sizes of tanks are your diy sumps made out of and what other things are good options for making sumps out of. I have a 55 gallon main tank and need something relatively narrow.

[dirtyclownfish]

bump

[Napervegas]

20 long is nice low and long, should fit under your stand. Another option is to use your acrylic baffels and put "weatherstripping" like for doors of houses on the baffels and wedge them in the sump. works great for short baffels.

[rsw686]

My sump is a 20 long, I would think that would fit under a 55. I tried the weatherstripping and I was afraid over time it was going to break the tank. The acrylic piece with weatherstripping has to put a good amount of force out towards the glass to hold it in place. If you don't have a tight enough fit when one compartment fills it will push the baffle out of place. I was just worried that multiple baffles exerting force would cause the tank seems to fail down the road.

[tinmanny]

I have a 90 main and a 30 glass with plex baffles that are only 1/8 thick and flexable I sanded the edges real good and used silacone and they even flex a lot with water height but it is 2 years now and still holding very well
Good luck
Manny