Need advice on a temporary/ reversible glue/sealant to use inside a fish tank

[KittenFishMom]

I want to create a "moon light" pond in my 55 gallon tanks build. I will put a light under the glass, and have it shine up through a cleared area in the bottom on the tank. I will be able to turn the light on and off as I wish, or set it on a timer.

I was thinking that sticking the bottom of a glass pie plate/pan to the bottom of the tank would help keep substrate and such from drifting into the "pond" area. I could ever glue a small planted island  off center for fun. I would surround the"pond" with small stocks to cover the sloping walls of the pie plate, and soften the perfectly poundness of the pond.

I think anything I glue inside the pie plate could be permanent, but I would like to be able to remove the pie plate itself for a future build if I don't like it where it is.  It would be good to be about to seal all around the plate to keep stuff from getting between the plate and the glass. And someday in the future have the option to dissolve the seal and remove the plate from the tank, say if I want to do another build, or sell the tank.

I think it could be so cool to watch fish swim over the pond in the dark, and see the surrounding plants lit from underneath.

So, I am looking for a reversible sealant or glue that could last year and won't hurt the fish.

I look forward to your responses !!!!

 

[Flumpweesel]

Silicone sealant can removed with a razor blade. What I would do is run a thick bead of silicone around the rim of the bowl and let it dry it should then act like a non slip rubbery grip so bowl won't move unless you lift it. Which will make cleaning easier

How are you going to deal with water under it going iffy because it won't have any flow?

[billango]

I also think silicone would be my first choice. If it's on flat glass, youll probably be able to just peel it off when you want to but it should pretty much stay in place on its own. I think another viable and fish safe option would be hot glue but I don't personally have experience with hot glue in aquariums. 

[KittenFishMom]

@Flumpweesel If I completely seal the edge that touches the glass, no water should get between the pie plate and the tank glass and get iffy. American pie plates are round, low, with sloped edges. I would put the bottom of the pie plate against the glass of the tank.

Edited October 19, 2022 by KittenFishMom
typos

[Flumpweesel]

Got ya.

I would still be tempted to keep it liftable using the silicone to make it grip should suffice especially when substrate had been added around it. I used I similar method for some back panels on my tank and they did not budge