View Full Version : Acrylic vs Glass Sump Baffles

07/12/2017, 07:54 PM
I have always used custom cut glass for my DIY sump baffles, but after seeing this for sale Refugium Kit (http://www.ebay.com/itm/REFUGIUM-KIT-for-30-x-12-x18-29-30-GAL-aquarium-Adjustable-water-height-/162433942963?var=&hash=item25d1d145b3:m:m8ENBjpdWC5vE8trVKffAAQ) it made me wonder.

I've also always heard that the silicone doesn't bond as well to acrylic as it does to glass (which the first sump that I made in college would testify to).

That seller recommends this silicone (http://www.homedepot.com/p/GE-2-8-oz-Silicone-Sealant-GE-57/202038072) for his products. I've never seen one specially for plastics before.

With acrylic easier to source and work at home, I was wondering if anyone has any experience with this.

07/13/2017, 04:44 AM
Like with anything there are advantages and disadvantages either way.

Acrylic does indeed not bond as well to silicone but if you make a good joint its plenty strong for a sump where there shouldn't be a lot of pressure. Acrylic can expand slightly when it's wet, so the baffles should be slightly undersized.

If you use glass, get the edges relieved or polished, or do it yourself with sandpaper, so you don't cut yourself - fresh cut glass is very sharp. Don't use thin picture frame/window glass from a hardware store, it's way too thin and fragile.

That silicone is fine but that's an awful small tube. Get a caulk gun and use a full size tube.

07/13/2017, 02:54 PM
My sumps are always re-conditioned tanks, so glass baffles are preferred chez moi. Glass adheres better with silicone and doesn't expand or warp like acrylic. Just get the edges polished as the prior post notes if you go glass.

07/13/2017, 06:32 PM
I'm familiar with glass baffles, as most of what I have made in the past was with them. However I always end up adding some sort of egg crate strainer on top, where the acrylic could have weirs cut. Also I do like the idea of variable heights for the chamber, which is again much easier to do with acrylic.
Just polling the crowd.

07/14/2017, 02:26 PM
There have been many hundreds/thousands of glass sumps make with acrylic baffles..
and quite a few posts about those baffles falling over after X amount of time or cracked glass tanks because of the acrylic expansion..
And plenty of people that its worked just fine for also..

There is little force on baffles in a tank so its certainly possible to use silicone (regular GE type 1 works fine too) and basically "wedge" those baffles into place.

Is glass "better".. sure is.. Is glass 100% necessary.. no its not..
Do you feel lucky punk? ;)

07/14/2017, 07:40 PM
I don't think u would have any issues with that kit. The sock holder actually sits on the trim, so u don't have to rely on the silicone to hold the wieght. As far as the baffles, think of it as wedging the baffles in place with the silicone & it will last for a while.