Midas Posted March 16, 2004 Report Share Posted March 16, 2004 Here is my effort at making a concrete background for my 4ft Malawi tank I have recently setup. What do you all think? Quote Link to comment Share on other sites More sharing options...
Robbo Posted March 16, 2004 Report Share Posted March 16, 2004 Not bad Midas! How much concrete did you use? Cheers Robbo Quote Link to comment Share on other sites More sharing options...
Caryl Posted March 16, 2004 Report Share Posted March 16, 2004 Looks good. How do you clean in it? Quote Link to comment Share on other sites More sharing options...
Midas Posted March 17, 2004 Author Report Share Posted March 17, 2004 Not much concrete involved really, maybe about 10-15kg. Its just a 2-5 mm layer of concrete over a polystyrene base. What I did was cut out individual rock size pieces of polystyrene, shape them with a bread knife (and fingers) into something resembling a rock, heat them gently over a portable gas stove to melt the polystyrene enough to create a smooth surface, then I siliconed these rock shaped pieces together. After that was dry I coated it in concrete (I used easycrete with all the pebbles larger than small sand grains sifted out with a collander). The end result actually floats (just) so it is very light weight compared to a conventional rock wall. I was going to use a coloured sealer to cover the polystyrene but this was much more expensive and a layer of concrete is much more robust. I have had trouble keeping the pH down and couldn't put any fish in for a couple of months while the concrete cured (releases calcium hydroxide). However this seems to have stabilised out pretty much now, and the pH only rises (if left alone) only by about 0.1-0.2 units per day. I have been controlling it at 8-8.2 by pH testing and addition of hydrochloric acid (about 5ml of 2M HCL every 1-2days). Cleaning it?? I have put a pleco in there and he seems to like munching the algae off it enough not to worry about any additional cleaning at this stage. A bit of algae on there will make it look better anyway probably. Quote Link to comment Share on other sites More sharing options...
Caryl Posted March 17, 2004 Report Share Posted March 17, 2004 By cleaning I didn't mean algae, I meant the uneaten bits of crud that will get in underneath. Sounds like a great idea. I might try it myself. There are some sites out there detailing how to do similar creations. I think polystyrene is the way to go. Quote Link to comment Share on other sites More sharing options...
Midas Posted March 17, 2004 Author Report Share Posted March 17, 2004 It's in three pieces so they can be removed if necessary for cleaning. Normally though I have just been moving the stones holding it in place at the front one at a time when gravel vac'ing and cleaning that way. I have also tried to direct the water flow from the canister filters so that as little crap as possible ends up in behind the background. If I did another background like this I think I would either put some kind of concrete dye in it or incorporate some black sand into the cement mix to try and darken it up a bit. I guess once the algae gets established the lightish concrete colour won't be so noticable. Quote Link to comment Share on other sites More sharing options...
Caryl Posted March 17, 2004 Report Share Posted March 17, 2004 Someone (pies I think) once suggested a spray bar correctly angled along the bottom of the back wall would direct any crud back out to the front where it could be reached. Quote Link to comment Share on other sites More sharing options...
Midas Posted May 10, 2004 Author Report Share Posted May 10, 2004 An update if anyone is interested: I am now no longer having to battle to keep the pH down with the addition of acid. The pH now decreases over time without any help, so I am having to buffer it up with crushed shell and sodium bicarbonate to mantain the pH at 7.8-8 (like I would normally have to in any other tank without concrete present). I'd say this means the background has finally fully cured. Only took 5 months :roll: . Quote Link to comment Share on other sites More sharing options...
Caryl Posted May 10, 2004 Report Share Posted May 10, 2004 Any chance of an updated pic? Quote Link to comment Share on other sites More sharing options...
NPnewbie Posted June 12, 2004 Report Share Posted June 12, 2004 Nice looking background...can you tell me how did you colour it? Did you paint it? I can't decide weather to make my own or buy a resin background. Quote Link to comment Share on other sites More sharing options...
Midas Posted June 13, 2004 Author Report Share Posted June 13, 2004 I didn't put any colour into the concrete mix. The colour in the picture is just normal concrete colouration with a bit of green and brown algae growing on it, which the Bristlenose keeps under control. Apparently there are concrete dyes available that you can add into the cement mix for added colour (e.g. brown, black etc.). I didn't bother looking into this but I probably would experiment if I ever made another one. Before I decided on using concrete I was just going to paint the polystyrene and then seal it with some kind of water proof compound. However this option looked too expensive in the end (at about $20 for a small tin of clear sealer which probably wouldn't have been enough to cover the entire backgorund - as opposed to $9 for a 25kg bag of ready mix concrete). I also thought concrete would be easier to get to look natural (I didn't back my painting skills) and additionally there was a risk that the water proof sealer (I was considering using waterbased polyurethane) would not last much more than a couple of years in a completely submersed environment before starting to peel off. Quote Link to comment Share on other sites More sharing options...
malawi_man Posted January 22, 2005 Report Share Posted January 22, 2005 the polystyrene bit sounds a bit fiddly, where did you get the polystyrene from?? Quote Link to comment Share on other sites More sharing options...
Midas Posted January 23, 2005 Author Report Share Posted January 23, 2005 yes it was fidley, and messy. Even thouh I made it the garage I was still finding little bits of ploystyene around the house months afterwards. But I am quite happy with the results and would repeat the process if I wanted another one. For the polystyrene I had some old stuff ex-packaging that I just broke the bits off of. This made it even more fidley but it was free. It is possible to buy sheets of polystyrene around 10cm thick which would be quite good for the job. Quote Link to comment Share on other sites More sharing options...
malawi_man Posted January 23, 2005 Report Share Posted January 23, 2005 is that the socofoli in the middle?? what is the brown fish on the left?? Quote Link to comment Share on other sites More sharing options...
Midas Posted January 23, 2005 Author Report Share Posted January 23, 2005 The socolofi is indeed the blue blur in the middle of the tank and the brown fish is a bumblebee cichlid that we used to have. Quote Link to comment Share on other sites More sharing options...
Caryl Posted January 24, 2005 Report Share Posted January 24, 2005 We always have tons of polystyrene as all our computer parts come packed in it. I hate taking it to fill the dump and it is toxic if you burn it. Quote Link to comment Share on other sites More sharing options...
critter_guy Posted January 24, 2005 Report Share Posted January 24, 2005 so...Midas...when are you making me one lol :lol: :lol: its really good i really like it Quote Link to comment Share on other sites More sharing options...
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