I have some plastic plants but i have to burry them in the gravel to weigh them down, however, i dont have gravel. What can i do so that they wont float? Some plastic plants i saw had some "epoxy" or resin type base...I'm thinkin of plaster of paris, is this safe? If not, what other suggestions do you have?

I thought plaster of paris fell apart when wet? Maybe I'm thinking of something else though

I wouldn't try plaster of paris. Instead, how about some aquarium sealant and some gravel? I think I saw that suggested somewhere on the forums. Anyway, just use the sealant to glue some gravel to the bottom of the plant.

I'm pretty sure plaster of paris does dissolve in the water.

Use aquarium silicone and gravel.Please don't use plaster of paris its not designed for use in tanks.Another option is buy the metal weights from your LFS that are usually used on live plants and weight them that way.

Cool! Thanks for the advice. Will surely not use it on my tanks

OK, old fashioned Plaster of Paris has been used in large tanks and fish ponds for years and years. But NOT for weighting down plants....

Plater of Paris, as it dissolves wil liberate Calcium and Magnesium carbonate (limestone) - this calcuim is very beneficial - particularly to young fish for it helps develop strong bones.The carbonates relieased are the buffer of your tank - raising and stabilizing the pH in your tank. Usually, no matter how much you use, youcannot get the pH about 8.3 though - an adequate level for goldies....

a 2 X 2 X 2 inch puck of Plaster of Paris in a 30 gallon tank is perfect for maintaining buffer and pH in water that is very low in kH, etc. RO water benefits well from PofP pucks......

Use ONLY high grade PofP - pure. Limestone 50%, Gypsum 50%. No hardeners, no setting agent, no binders, no stabilizers. Be careful that you use the GOOD stuff. Do not put it in the water until it is dry, dusty and chalky. It must be competely dry to work right..

Let me see if I can find an internet link.....

Here it is:

http://www.pondsplus.com/Infofiles/art02.htm

This article has 75% Limestone, 25% gypsum. Mine has 50/50. I am assuming both work.

How about taking polished river rock ( you can get a small bag of them at the 99 cents store) and hot glue gun ( the glue guns you use for crafts with the sticks) and glue a couple river rocks to the base of the plant, let it cool and cure and then burry it under gravel. The hot glue gun glue is safe for the tank. I have repaired bubble walls tubing with it and glued other items in the tank

I wouldn't trust the glue from glue guns in my tank, I'd stick with silicone sealant... :-/

I have used it many times with my goldies and betta with no ill effects. Have to wait till it cools though. Rather use it than sealant that has lots of toxic fumes

Thanks bettaqueen! Just followed your advice and now i have my plastic plants in my tank without them floating away. Thanks you all for the advices.

EWWW plaster of paris desinigrates when it comes in contact with water, I tried building a fountan this way and it never worked. . . . .

Just running through the forums and I spotted this.

I did this *exact* thing last week with my plants, and the glue separated from the rocks affter being in the tank for a day.

If anybody else is looking for a way to weight down their plants, in my experience, hot gluing them to polished river rocks doesn't work... the glue just won't stick.