Jeremy321

ok i want to put a heartagram in my fishtank for those of you who dont know what that is look what could i make it out of? do you know where i could buy one? would it harm my fish.

sirdarksol

Whether or not HIM's sigil will hurt your fish will depend on what it is made out of.
If you have access to a sand-blaster, you could make it out of a piece of glass, round the edges (so they don't cut the fishes' fins), wash it really well to get rid of the excess sand, and mount it however you want.
Otherwise, you could use acrylic, stainless steel, any sort of neutral stone, or neutral driftwood. There are aquarium-safe paints (be sure you follow directions on letting it dry).
The coolest looking choices will also be the most difficult to do (sorry), unless you're friendly with an art teacher on a college campus.
Be sure you do not use any metal that you aren't sure is stainless steel. Copper is a commonly used metal in alloys, and will kill your tank if it begins leeching into the water. Same with glazes. If you were to use ceramics, grill someone who's really knowledgeable about the subject and make sure there's nothing but silica, grit, and maybe iron in it. Blues and greens are usually made with copper in one form or another. Many of the other colors are made with heavy metals.

darkwolf29a

You could also make it out of Sculpey. Just make sure to bake it as directed, and then find some marine grade resin, sold in most hardware stores. I've seen that used many times.

Also, you could do some more work, make a mold, and cast it out of resin, like all other aquarium decorations are made of. Either way should work like a charm.

sirdarksol

Possibly the best solution for someone who doesn't have access to a crafts lab.