DIY sump baffle question

OK, so I am going to call the glass shop to get some glass cut and I need to know how wide get it cut. I have a standard 55g. from inside to inside it is exactly 12 inches. So my question should I get it cut to 11 3/4 for a 1/8 inch on each side. is that OK. I will do 3 9 inch pieces and 1 15 inch piece. 1/4 inch thick.

 

Yes that is a good idea.

 

I made mine as close as possible to the actual length. Makes it easier when you go to gluing it in.

 

The best thing to do is to actually take the tank to the glass shop. Once they make the first cut, they can set it in place and see. You dont want it be off by even a 1/4 inch as you will have to add way too much silicone to get them in place.

 

I made a sump from a 40gal breeder tank and used custom cut glass for baffles. I'll post a link of how I did it on from my 90 gal post.

 

Very important, have them bevel the edges to what is exposed to you so you don't cut yourself while doing maint and round the corners at the bottom to prevent it cutting the silicone on the tank during the install.

 

When I built my 20l sump the dimentions I gave the glass shop were 1/8" shorter than the actual depth of the tank that left me about 1/16" on each side for the sylicone. Worked good for me.
+1 on the beveled edges.