Back to Nature bkgrnd?

[tjbray]

I'm making a Back-to-Nature style background for my 72 gallon bowfront out of styrofoam and cement, with the goal of hiding the aquarium mechanics while providing a natural-looking environment.  Does anyone know what type of cement mixture I should use?

[luvfishies]

I know of someone who makes their own decor on another board...hang on I'll go search her  thread for you.

http://www.fishindex.com/forum/showthread.php?s=&threadid=17861&highlight =rocks

there it is.it might help.

another aquarist did what you're doing with styrofoam and fishie-safe paint...turned out really well too....

rats, the page is no longer there, and that's too bad...he actually used a resin....

[tjbray]

I've decided to go with a masonry mortar mix.  So far, the coatings have gone on quite well.  I went with straight gray for the base layer, next I added some 'veins' of a charcoal color, followed by a buff-brown (kinda like terra cotta, but more 'muddy' lookin) within an hour of putting the charcoal cement.

I then took a paintbrush, dampened it, and used it to smooth out the roughness.  Every now and then I flipped the brush over, and gouged the brown through to the black, but not into the styrofoam, to give a look of stress cracks and veins.  It looks pretty good as it is, but tomorrow I want to mix some more straight gray and lightly wash over areas for more color depth.  For my not being much of an artist, I'm really happy with the results so far.  

After I get the glass cleaned off, I'll snap a pic and post it on here.  It ought to look pretty cool when it's full of water (it's a 72 gallon bowfront). ley*

[tjbray]

Well, I'm not at all pleased with the additional gray.   :-/
Now I gotta go back and cover that part up.  If I can get it back closer to how it was, I'm going to leave it that way.  I'll post the pics in a couple of days. The texture from using mortar as opposed to straight cement (which I wasn't sure whether it would hold up under water) is obviously more rough, but I think it gives a natural sandy appearance (at least, until I tried to add gray highlights).

Total cost of my project has been minimal:
  72 gallon bowfront tank:                $65.00
  3 tubes of GE silicone:                     10.50
  styrofoam:                                      4.50
  mortar mix:                                      6.50
  cement tint (charcoal & buff)            10.00

  total:                                          $96.50

The stand and canopy are DIY as well (and nearing completion).
They are constructed from weathered cedar, which I had from taking down an old privacy fence on my property.  I'll post all of that stuff on another thread when I get it all done and the tank is stocked and running.

[clothahump]

Just wondering what you are going to do about the lime leaching out of the mortar?

Thanks for the link Luv, went off on another link from there and spent ages looking at alternative building methods for houses.
Now where did I put the concrete mixer?

[tjbray]

The original idea for this project came from an out-of-print book I have titled, "The Living Aquarium," by Peter Hunnam, Annabel Milne, and Peter Stebbing.  I originally bought the book for the table they have for finding the correct glass thickness necessary for different sizes of DIY tanks, but I found their section on hiding the mechanics in concrete background castings, and began searching the web for some examples. Here's a link to a really nice one I found, by the way:

http://cichlidinspiration.net3services.com/show_articles2.asp?id=13

In my book, the authors state that allowing it to sit a month before adding water should cure it deep enough to prevent alkalinity problems.  After that, I'm going to run the tank for a month with no fish, using a Penguin Bio-wheel 330 only (I'm working on a DIY trickle filter as well for it), and I'll be monitoring the before/after ph level weekly before doing 25% water changes.  If everything looks okay up to that point, I'm going to drop to 10% water changes for 2 weeks, still monitoring the ph. If it appears that I'm going to have problems with maintaining the ph, then I will apply a clear resin coating to the background, although this will not look as good as leaving it alone.

With the rather thin layer of cement (thanks to the styrofoam foundation), any seepage I do have should be minimal, but I'll always monitor it even after the fish have been added, mainly to help me to decide whether I want to use this method for my next big project, a DIY tank.

The tank is going to hold rift lake species of cichlids, so a slight raise (within reason) of alkalinity each week can be tolerated, but I'm not going to put the fish through undo stress if it causes wild fluctuations.  I'll let you know what the numbers are as I test.  I'll try to snap a pic of the tank and post it tomorrow.  My wife wants me to take a night off from working on the fish stuff. ;D

[tjbray]

I've got some pics of the finished tank (will not be filled with water until late August, though), but I have NO idea how to attach the pic to this post.javascript:undecided()undecided  
If anyone can give me some pointers, either on the thread or via e-mail, I'd appreciate it.

[tjbray]

I had previously posted a link to an online photo album that I set up to show the tank so far, but apparently people weren't able to access it. *Here's a link to my local club that has the pic in it:

http://www.gcas.org/discus/messages/4/3107.html?1028049131

Hopefully those interested in trying this project will be able to see it now!