Fish-Safe Cement?

[ScatMan]

i'm looking for a fish-safe cement. i want to tile the bottom of a glass tank but the tank has a 2" strip of glass around the bottom inside edges. i need cement to level out the bottom so i can lay the tiles flat, any suggestions?

will regular cement work, or will that leach nasties back into the water?

 

[littlewangzfan]

You can use plexiglass with the same thickness.

 

[ScatMan]

plexi was really expensive, glass would be a lot cheaper, but still not as cheap as a bag of concrete.

i wanted to set the tiles in the concrete as well to level them off nice.

 

[littlewangzfan]

Oh yeah sorry forgot to ask about the tank size. How thick is the glass? How about styrofoam, the weight of the tiles will hold it down. As with cement I think the only way to make it fish safe is to let it leach out any chemicals w/c involves filling and draining the tank many times.

 

[ScatMan]

it's a 130g and i plan on doing the same to a 600 in the near future. if cement won't work i'll just use glass, but there's gotta be some concrete product that's fish-safe because i've seen plenty of concrete koi ponds...

 

[littlewangzfan]

Pls. post pics. I want to see how it turns out. Good luck.

 

[deeda]

I have used Quikrete brand Quick Setting Cement and Quikrete Surface Bonding Cement (fiberglass reinforced) when building my backgrounds with no long term issues. I do agree with Noel that you should flush any cement product multiple times to reduce the alkalinity from the product while it is curing. There will still be some residual alkalinity for a few months but I have not noticed any problems with my African cichlids.

However, I don't know that it would be wise to apply cement directly to the bottom of your tank.

What you can do is make a 'drop in' tile bottom using cement and egg crate ceiling tiles. Just cut the egg crate tiles to your tank bottom dimensions, you don't want a tight fit. Remove the egg crate from the tank, apply the cement to the egg crate by filling in all the holes, build up a layer above the holes to accept your tiles and embed them in the wet cement. Once the cement cures, you can soak the 'drop in' background until the alkalinity is reduced.

I would recommend making these individual panels in at least 4 pieces as they will accumulate weight from the cement and the tiles and it will be easier to install in the tank. It's just a thought and it is the same procedure I used to make my real rock background for my tanks.

 

[ScatMan]

Oh yeah sorry forgot to ask about the tank size. How thick is the glass? How about styrofoam, the weight of the tiles will hold it down. As with cement I think the only way to make it fish safe is to let it leach out any chemicals w/c involves filling and draining the tank many times.

will do, thanks for the help!

 

[ScatMan]

I have used Quikrete brand Quick Setting Cement and Quikrete Surface Bonding Cement (fiberglass reinforced) when building my backgrounds with no long term issues. I do agree with Noel that you should flush any cement product multiple times to reduce the alkalinity from the product while it is curing. There will still be some residual alkalinity for a few months but I have not noticed any problems with my African cichlids.

However, I don't know that it would be wise to apply cement directly to the bottom of your tank.

What you can do is make a 'drop in' tile bottom using cement and egg crate ceiling tiles. Just cut the egg crate tiles to your tank bottom dimensions, you don't want a tight fit. Remove the egg crate from the tank, apply the cement to the egg crate by filling in all the holes, build up a layer above the holes to accept your tiles and embed them in the wet cement. Once the cement cures, you can soak the 'drop in' background until the alkalinity is reduced.

I would recommend making these individual panels in at least 4 pieces as they will accumulate weight from the cement and the tiles and it will be easier to install in the tank. It's just a thought and it is the same procedure I used to make my real rock background for my tanks.

why is that?

i hear that concrete can expand slightly before curing, and have been advised to put foam expansion pad around the sides before pouring it. is that solid advice?

i'm looking at this hydraulic quikrete stuff, any experience with that?

 

[deeda]

I would say the main reason for not applying the cement mix directly to the tank bottom is, how would you ever remove it?

I have only used the Quikrete Hydraulic cement for plugging leaks in basement walls.