plastic cardboard in the tank??

cracker · Nov 2, 2017

Hello, I'm considering lining a baffle (in the sump) to block light from the refugium. I found a 24 by 36 inch sheet of black plastic cardboard. It was with the acrylic they sell & cost 10 bucks. They had white also. So I "think" it would be safe to submerge it but not sure. The white still let light thru where as this black stuff ,nun at all.
Any ideas how to fasten it with out draining the sump? I was thinking some superglue gel perhaps.Thanks

nautical_nathaniel · Nov 2, 2017

That material will be okay in a tank, SB Reef Lights makes a "pod hotel" that is made with that stuff. You could probably fashion some plastic clips or something to hold it at the top or possibly find some nano sized cleaning magnets to keep it held to the baffles or wall of the sump. Don't use regular magnets unless they are sealed with something, otherwise they will corrode due to saltwater and leach heavy metals into your water.

cracker · Nov 2, 2017

great ideas ! I have magnets from old power heads. Thanks !

Also out of curiosity ,what material would be good to seal magnets ? I have a bunch of rare earth magnets I got from my Bro. He used to repair cat scan machines. He says the newer machines don't use them any more. I been using them as refrigerator mags. I assure You 'nothing" falls off .

nautical_nathaniel · Nov 2, 2017

cracker said:
great ideas ! I have magnets from old power heads. Thanks !

Also out of curiosity ,what material would be good to seal magnets ? I have a bunch of rare earth magnets I got from my Bro. He used to repair cat scan machines. He says the newer machines don't use them any more. I been using them as refrigerator mags. I assure You 'nothing" falls off .

I've heard of sealing them in epoxy but I've never tried it myself. I would suggest using something super sturdy like maritime epoxy and making a little mold to put them in as you coat them. Put an 1/8" or so coating around the side of them. After curing, get some sand paper all the way up to 800 grit or so and smooth them out :)

You could also take some acrylic, bore out an exact space for the magnet, and then backfill with epoxy, that way you could make a row or specific shape of magnets that would stay together and apply even pressure across the black plastic stuff.

cracker · Nov 2, 2017

Well that was a fun project. It's just a rough finish but still works pretty good. So now The light is shining thru the bottom,reflecting off the floor & shining into the return section from below ! I'll put something under there to block this reflective light. Here are a couple before & after pics.