Styrofoam/Cement Background

E

ejmeier

AC Members
Jun 15, 2003
60
0
0
www.nano-reef.com
I have reposted this in this forum as there wasn't any replies in the DIY section, or hardly any views for that matter.

Well, I got this idea from another site, and decided that this would be a good idea for a background for me too.

Here's what I did:
Bought a 8' x 4' x 2" piece of styrofoam for like 7 - 8 dollars at HD. Had to cut it into three pieces to fit it into my car. This was WAY more than I will ever need. :rolleyes:

I also bought a 94 lb. bag of Type I Portland Cement. (Again, WAY too much, I probably only used like .01% of the whole bag.) It only cost around $7 and it was the smallest - and only bag that they carried at HD.:o

I cut the styrofoam to the right size to fit my background (a 33g long that is 48" x 12" on the back). Then I just started gouging away the styrofoam with a long knife until I got something that I thought looked natural. I was going for a rock-cliff type of a look, and hopefully it turns out semi-realistic.

I really do not consider myself artistic at all, (seriously, I have no artistic talent AT ALL!) but from all of my half-planned/half-spontaneous gouging I came out with something that looks pretty decent. :) If you are considering doing something like this, but doubt your artistic abilities, don't worry, a monkey could do this! I say go for it.

After this, I mixed some water with the portland cement until it was a gel-like consistency. I then used a paintbrush and painted the cement on.

It is drying, or "curing" as we speak. :D

My question is: I've never used this cement stuff before, and I think I mixed it wrong. Are you supposed to add sand into the mix as well as water? Does anyone know the effect of using just cement and water will be?

Also, is there any way to preserve the cement mix for future uses? I have heard that it hardens in the bag once it is opened. Just wondering how long I have, and if I should store it in something other than the bag - a 5 gal bucket w/ lid perhaps?
 
Try experimenting with different portland/sand mixtures. You might come up with one you really like. Portland with sand has more strenth than straight portland. I don't honestly know what straight portland will perform like, especially under water.

If you 'spritz' the painted on mixture with water from a spray bottle as it is curing for the first few hours I believe it will cure harder than if it dries out too quickly, IMO.

If you keep the hernia producing bag of portland out of humidty & dampness and at room temps, it should stay usable for a couple of years. If you don't need that much, store some away in some massive ziploc bags as humidity is your only enemy in this case. You could also store it in a tied off garbage bag.
 
Like said before, not mixing sand in makes the cement a lot weaker. So you will have to see what happens as the cement may start cracking.

One problem with cement and sand is that it can (and probably well) change the water chemistry a little. Generally not recomended if you are going to keep fish that requires neutral to acidic pH but with Cichlids it will be fine.

To avoid the use of cement there is another way which uses expanding polyurethane canes which you spray either directly on the back of the tank or on a piece of acrylic. You can then push stones in the polyurathane before it cures and you will end up with a similar effect except you will get away with even less artistic talent....
 
Originally posted by a_free_bird73
To avoid the use of cement there is another way which uses expanding polyurethane canes which you spray either directly on the back of the tank or on a piece of acrylic. You can then push stones in the polyurathane before it cures and you will end up with a similar effect except you will get away with even less artistic talent....
Click to expand...
This is hilarious. At the same time as you wrote this, someone else commented on another site about the same thing. You see, I wrote an article which appears in August's edition of Reefkeeping Magazine over at reefcentral.com about using polyurethane foam as backgrounds. Hehe, I know all about this technique..:D

Anyway, I painted on a second coat of concrete to my background, this time mixed with 1/2 sand, and it looks great. I just siliconed it to the back of my tank, and all I can say is, WOW!:)

I can't wait until the tank is all set up and running.

I plan to fill the tank with water soon and allow the cement to start curing/leeching out any lime. I will monitor the pH levels and see how things go.
 
ejmeier, would you do us a favour to satisfy our curiosity? I'll assume you knew your tank parameters before you put the background in the tank. Would you measure pH, GH and KH as time progresses just to see what changes? Also it would be good if you could give us the approximate volume of cement/sand mix and the volume of tank water.

If you are using plain portland and clean sand and none of the above parameters changes drastically, then I see no problem using it.
 
Actually, this is a completely new tank setup. My fish are in the next room, in a separate tank.

I will test the pH, and possibly the alkalinity. What is GH? Sorry, haven't really done this FW stuff, only salt.:)

Also, the results may be somewhat... skewed. I used aragonitic sand mixed into the cement - not silica based. It buffers the water and is simliar to crushed coral, so I think that no matter what, there will be a measurable impact.
 
Originally posted by ejmeier
Also, the results may be somewhat... skewed. I used aragonitic sand mixed into the cement - not silica based. It buffers the water and is simliar to crushed coral, so I think that no matter what, there will be a measurable impact.
Click to expand...
As long as the results don't change too drastically and the final results are within safe parameters, it should be a viable solution.
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom