Sealing Concrete?

[SejRamkas]

I am planning to construct a rock wall background for my tank out of foam covered in concrete. I would like to be able to seal the concrete up so that my plecos and discus dont try to peck the pieces of concrete off and harm themselves. Can anyone recommend some kind of good sealer that is aquarium safe? Do I need to seal the concrete, or should it harden enough that it doesn't need any additional protection?

Thanks!

[Northwoods Discus]

There are a lot of you tube videos and info on making 3D backgrounds and plenty using cement. Personally I had to add cement to some drift wood to get it to sink. I encased it in epoxy. That seems to have worked out great. Does not affect my chemistry.

[SejRamkas]

There are a lot of you tube videos and info on making 3D backgrounds and plenty using cement. Personally I had to add cement to some drift wood to get it to sink. I encased it in epoxy. That seems to have worked out great. Does not affect my chemistry.

Yea I have done this before for a reptile cage that was for a bearded dragon so I am familiar with the process and didnt have to worry about humidity or water. What kind of epoxy did you use to seal it? Does it give it a shiny fake looking sheen to the cement?

[Northwoods Discus]

It is not visible. The wood is also encased in epoxy. It had a shine but has lots of algae etc and looks great now. I used the bar top epoxy from Home Depot. Once epoxy cures it is non toxic. You will want to make sure the cement is fully cured and dry before applying the epoxy. I used several coats to make sure of complete coverage.

[troysdiiscus]

I made my 3d background using cement. Never had an issue with them chipping away the cement. Just takes along time for the ph to level it self off and stop leaching into the water. After about 3 to 4 weeks was ok, ph was still a touch high but stable.
http://i1337.photobucket.com/albums/o661/troyndeb/008_zpsa993ff65.jpg (http://s1337.photobucket.com/user/troyndeb/media/008_zpsa993ff65.jpg.html)

[SejRamkas]

So would I be able to avoid this ph swing by sealing with epoxy? How much of a ph swing are we talking here? I'm just worried that my plecos will be able to eat off the cement, and also want to be able to scrub it without worrying about chipping it away.

[troysdiiscus]

Intially when I finished it with about 4 coats on it, ph off the background was about 11 or higher for about a week or two before lowering slowly that took about 2 or 3 more weeks. Ph was finally stable around 8 or so. Alot of soaking, rinsing, soaking rinsing. It takes awhile, I love it looks great but took dang alot of time and work. Took alot longer to cure than to make it. You can scrub it lightly to remove algae and such. When I setup my 110 gallon thought about doing it but got to thinking and not...bought a slimline rocky background and installed, opened the box, washed and trimmed it and was done!!!!Very easy and easy to clean without taking up alot of space. LOL I loved designing it and the whole project was fun one time..lol Good luck....

[troysdiiscus]

Oh and to answer your question about using epoxy, dont know if that application would be feesaable
So would I be able to avoid this ph swing by sealing with epoxy? How much of a ph swing are we talking here? I'm just worried that my plecos will be able to eat off the cement, and also want to be able to scrub it without worrying about chipping it away.

[SejRamkas]

Oh and to answer your question about using epoxy, dont know if that application would be feesaable

Why would using epoxy not be feasible?

[troysdiiscus]

For me it wasnt, I have never used it before so cant say...I do know that when I was doing mine I researched the use of epoxy and could not find any clear answers so just didnt use it.

[SejRamkas]

I believe its used pretty often in the marine aquarium hobby, so if it can withstand salt water I don't see why it wouldn't hold up well in fresh water.

[Cullymoto]

Search out a source for ecopoxy. It is a very safe two part epoxy with no v.o.c. I used ecopoxy in my living room with no ventilation. It was completely odourless. It is non toxic when wet or dry. Very very safe epoxy. Dries clear and solid.

[SejRamkas]

What about using krylon fusion clear coat as a sealer? I know krylon fusion has been used in many tanks by many people including myself with no harmful results, so would the same apply here? Would it coat enough to prevent the concrete from raising the ph of my tank?

[CrazyAngels]

What about using krylon fusion clear coat as a sealer? I know krylon fusion has been used in many tanks by many people including myself with no harmful results, so would the same apply here? Would it coat enough to prevent the concrete from raising the ph of my tank?

Sej, are you saying that you use the Krylon in the interior of the tanks???

[SejRamkas]

I have used it to paint PVC parts before after allowing it to cure for more than a week with no ill effects at all. Many people recommend using Krylon Fusion in aquarium applications as being fish safe. I have never had a bad experience with it.

I think I found the epoxy I am going to use. It's pretty inexpensive compared to the other brands (mainly because I can buy it in the small 16 oz. quantity which will be plenty for my use). see link below. Only thing I am concerned about is there is no UV protection with this epoxy. Would this be a problem?

http://www.shopmaninc.com/epoxy.html

[troysdiiscus]

I know the 635 3:1 is non toxic and should seal the concrete when its cured, as long as there are no blushing. Doing a thin first coat and second thicker coat should be fine. I had a buddy use it but not in an aquarium. I would be interested in the outcome. I know they say its non toxic but putting something that I dont know first hand in my discus tank was not a chance I was willing to take. I will be looking for your results...keep posted....

[SejRamkas]

I know the 635 3:1 is non toxic and should seal the concrete when its cured, as long as there are no blushing. Doing a thin first coat and second thicker coat should be fine. I had a buddy use it but not in an aquarium. I would be interested in the outcome. I know they say its non toxic but putting something that I dont know first hand in my discus tank was not a chance I was willing to take. I will be looking for your results...keep posted....

Yea I have my reservations as well, but I figured for the price its worth a shot. I've read a lot and it seems people say most if not all waterproof epoxies cure to be non toxic and inert. I will definitely be testing in a tank without the fish in it first and making sure water quality is not degraded before putting it in my display tank. I will be giving it at least a week or two to cure before doing so and if there is any funny smell at all after that I will not be putting it in my tank.

[SejRamkas]

So I emailed the company to inquire about the toxicity of this epoxy and here was the reply:

John,

Blush is considered somewhat toxic until removed with warm, soapy water and a white 3M scotch pad. Not all epoxies get blush. To be non-toxic to fish, make sure to remove any blush first.

Steve


What do you guys think?

[troysdiiscus]

yeah thats what I was thinking about the blush, I think if you put a thin layer first, then go back with a thicker coat, shouldnt blush again shouldnt. I am with you definately test it for a couple of weeks first. I am so skidddish about putting anything in my discus tank unless 100% sure its ok. Good luck let me know how it turns out.....

[SejRamkas]

I am pretty much trying to find the lesser of two evils. I can either leave it unsealed and worry about it raising the ph of my tank to undesirable levels, or try an epoxy that I'm not 100 percent sure on. Either way could lead to possible stress to the fish, but at this point I think the epoxy would be better.

If the rock permanently raises the ph level in my tank even after it has cured and been soaked then the ph will not be the same as that in my aging barrel, and defeats the purpose of the aging barrel all together. this is my main reason for wanting to seal it in the first place.

[Cullymoto]

Use ECOPOXY. not wet or dry is there a single toxic component. gives you the same final result as a regular epoxy, but with absolutely no drawbacks. I used it inside with the windows closed... it doesnt even have an odor. Most epoxies would have killed me under those conditions.

[SejRamkas]

Use ECOPOXY. not wet or dry is there a single toxic component. gives you the same final result as a regular epoxy, but with absolutely no drawbacks. I used it inside with the windows closed... it doesnt even have an odor. Most epoxies would have killed me under those conditions.

I'm assuming this requires purchasing the epoxy and hardner?

[CrazyAngels]

Sej, epoxies are 2 parts always, using one part alone would never cure. Some people call the 2nd part hardener and some catalyst, no matter what you call it, once mixed it will cure and harden. How hard the epoxy gets is a matter of the chemical components in the mixture.. Therefore you may see some epoxies which are kind of soft to the touch, yet some which almost cure as hard as steel and can actually be machined.

Anyway, the kit should always include both parts for you to mix once you are ready to use. HTH

[SejRamkas]

Thanks for clarifying Jorge. I thought all epoxies were 2 parts that were supposed to be mixed, just wasnt sure if this ecopoxy was different for some reason.

[CrazyAngels]

Sej, I would still contact them so they can recommend the right system for your application if you go that route. Good luck