So, I want to have one of those Underwater Waterfalls / Sandfalls.

I have just got a lot of river stones and used Mortar cement to put them all together.

Is this safe to use in my African Cichlid Tank?

I have heard it may lower the pH?

Please get back to me!

Here is the pic

http://imgur.com/CMlCmor

Cement will definitely alter the pH. It is highly discouraged to use this, as not only will the pH change but who knows what other chemicals are in the cement which will leech out into the water. I would really advise against putting that in your tank.

If you want to use anything, use clear silicone from the hardware store (use the ones which say aquarium safe, eg no anti-mold or anti-fungal ingredients). It's very easy to work with and can get surprisingly good results, and any excess can just be cut off after it has dried.

If using silicone, make sure to give it a full week to cure as it still leeches chemicals while curing.

Cement will definitely alter the pH. It is highly discouraged to use this, as not only will the pH change but who knows what other chemicals are in the cement which will leech out into the water. I would really advise against putting that in your tank.

If you want to use anything, use clear silicone from the hardware store (use the ones which say aquarium safe, eg no anti-mold or anti-fungal ingredients). It's very easy to work with and can get surprisingly good results, and any excess can just be cut off after it has dried.

If using silicone, make sure to give it a full week to cure as it still leeches chemicals while curing.

What If I coat it in something?

Cement usually raises the pH. You can get sealants that are used for concrete water tanks.

Cement usually raises the pH. You can get sealants that are used for concrete water tanks.

I use aragonite sand. Would this stabilize it for African Cichlids?

Again, you have NO IDEA what chemicals are going to leech into the water, and you would have to seal it pretty damn well. Aragonite raises the pH on its own, so you are only making the pH higher with cement.

How are you going to keep your landscape looking good when it is full of African cichlids anyway?

How are you going to keep your landscape looking good when it is full of African cichlids anyway?

What Sealent do you know of?

African Cichlids do not eat all plants In my current malawi tank no one eats any of my plants It's all about plant selection, research and trial and error!

Cement will definitely alter the pH. It is highly discouraged to use this, as not only will the pH change but who knows what other chemicals are in the cement which will leech out into the water. I would really advise against putting that in your tank.

Yeah, noone has ever successfully used concrete in a fish tank, it might be full of scary chemicals.

BTW, cement is what holds the concrete together, you don't use it alone.

Below successful examples, and instructions:

http://www.garf.org/class.html

http://www.fnzas.org.nz/fishroom/viewtopic.php?f=28&t=58285&hilit=concrete+back+background

http://www.fnzas.org.nz/fishroom/viewtopic.php?f=10&t=58184&hilit=concrete+back+background

http://www.cichlid-forum.com/articles/diy_aquarium_background.php

http://www.aquariumadvice.com/forums/f20/concrete-background-26290.html

http://www.reefcentral.com/forums/showthread.php?t=2037046

Another example; http://www.fnzas.org.nz/?p=2088

I used Cemix mortar rather than "concrete" though. I wouldn't be too concerned about it raising the pH, though I did find it increased the hardness a bit and the TDS considerably. Far from ideal for the type of fish I was keeping, but maybe not an issue for rift lake cichlids?

There are sealants out there, or you could just soak it (in rain water would be ideal) fior a while until the bulk of the leaching is done.

Another example; http://www.fnzas.org.nz/?p=2088

I used Cemix mortar rather than "concrete" though. I wouldn't be too concerned about it raising the pH, though I did find it increased the hardness a bit and the TDS considerably. Far from ideal for the type of fish I was keeping, but maybe not an issue for rift lake cichlids?

There are sealants out there, or you could just soak it (in rain water would be ideal) fior a while until the bulk of the leaching is done.

:gpo2:

I would just soak it fror a month or two doing full water changes each week and test the pH towards the end

I'd check TDS rather than pH.

I have used cement/concrete/morter (I do not know the difference in them, but it was for doing fencing post's.) in my mixed african tank, I soak it for several weeks with lots of water changes as previosly mentioned to let everything leech out of it.

I had no issues withit what so ever all the fish grew well, had great colours and breed regularly. It keept the ph high and hard, and with a mix of good buffers in the sump I had very little flucuations in my water readings.

I have used cement/concrete/morter (I do not know the difference in them, but it was for doing fencing post's.)

Cement is glue/binder, usually portland cement made from ground and baked limestone.

Concrete is sand+gravel/crushed rocks mixed with cement.

Mortar is sand mixed with cement.

The term "Asphalt" is also incorrect, by the way. Asphalt is a cement used in concrete which would most accurately be called asphaltic concrete. I suppose you could also have asphaltic mortar.

Sweeet, the things you learn on a fish forum