baffle issues

[jhaimes]

I have a quick question regarding baffles. I am using a 55 gal glass tank as my sump. I have some acrylic pieces and decided to use these as my baffles. My question is i have heard that acrylic can swell and end up breaking the tank at some point. Is this a bad issue that everyone but us newbies knows about? Will I be in trouble if i keep the acrylic baffles in place? Thank you for any advice...

[AngeloM3]

never heard of acrylic swelling....

but you will have problems silicone acrylic to glass. on a molecular level silicone doesn't bond acrylic to glass very well. I was told that a while back and thought "ehhh who cares" well a couple months later 2 of my baffles came completely loose and had to drain and redo a sump... not a fun project.

You better off going and getting glass cut... its better for the long run. Or build an acrylic sump and use the acrylic baffles

[chatyak]

Not sure about expansion... I know you can't use silicone though... weld on #4 I believe it is.

[phunkie99]

I've heard of acrylic bowing but not swelling

[mckaax]

you can use silicone weld on is only good for acrylic only. When you do acrylic on glass you have to use silicone. Acrylic should not expand, it will only bend when it has pressure on it.

[mckaax]

Also put the silicone on pretty thick because silicone does not stick well to acrylic.

[jhaimes]

Thanks for all of the replies so far...I have some aquarium silicone that i used to place the baffles with...so if i put the silicone on fairly thick will the water pressure bust the baffle seal and leave me with a mess. I figure I will apply the silicone a couple more times to be sure it is solid. Am i just asking for trouble?

[eb8919]

I believe it is plexiglass that swells and breaks. I built my sump with a glass aquarium and acrylic baffles and i have not experienced any issues, everything seems sturdy. On the other hand my friends acrylic baffles buckled and came loose. I think if you have the pieces cut precisely so theres no bending when you stick it in place, and add quite a bit of silicone (keeping it clean of course) you should be fine. I added quite a bit myself and i think in the long run, it helped. Good luck.

[Playa-1]

I would use glass baffles in a glass sump and just use silicone to secure them into place. Use the acrylic for something else.
Having the glass cut and polished should be inexpensive and likely a 24 hour turn around time.

[fishoutawater]

I have had to try and remove acrylic baffles that have been siliconed into a glass tank. To get most of them out I have had to break the acrylic.

[Toddrtrex]

I have acrylic on all 3 of my glass tanks. Used silicone for all of them. The oldest sump is 7+ years old and the silicone is holding just like it was on day one.

[reefaffinity]

If you lay the silicone down really thick on both sides of the acrylic panes you should be fine, but like Playa-1 said, cut glass panes would be the best. Make sure to get the edges polished if you do get glass.