******UPDATE******
Since the last update, i finished the cementing, I decieded not to sand it
though. I then did a coat of fibreglass resin. I choose the fibreglass resin instead epoxy resin due to availability and cost. I have also recently discovered that the fibreglass resin is completly inert once cured. So i did one coat of the resin, which took almost a full day to harden and cure. Then last night i siliconed the background in. I'll give that 24-48hrs to cure befor i add water.
If you notice in the picture i changed the design of the background alot. At first it was going to be a one piece background, but after seeing it in the tank and seeing how much space it actually took up, i decieded to do rock modules instead. Doing the modules saved me at least half as much space as it would have originally taken up. Befor the modification, i estimated it to take up around 30-35gals of space. Now, its around 15gals.
After the cementing the background is when i started the change.
I First took off the back layer of the background, doing that saved me 1.5inch of space all around. i then just cut the rocks
out and then fibreglassed them individually. after a day, i siliconed them in place. I had to place them in free hand as i had them numbered at first for placement in the tank, but the numbers wore off of most of them for some reason. I also discovered one of the rocks had been crushed while i was at work.... which ended up being fine, it was not needed anyway.
I still kept the large rock that hides the filter intake/output and the heater. Thats the only piece that was the only piece
that i couldnt cut out or thin. But i was able to cut the rocks off that were attached to it so it would match the other side.
After i was done the cementing/waiting till it cured, i thought that the light gray color of the cement looked ok, but not natural, so i decided to spray paint it with some light brown spray paint by krylon fusion. I only did a light mist to it, so that the gray would still show threw a tiny bit. when that dried, thats when i fibreglassed it all, sealing in the cement and paint, and also giving it a tough shell.
I may do a test fill tonight, but im probely going to wait another 12hrs or so.
One thing that i did mess up was the silicone, i got it in white(thought i grabbed clear), and it shows all of my mistakes/over use, so i still have a bit more of that to clean up befor i'll add water.
I ended up using GE I silicone as the aquarium made silicone i ordered was going to take another week to come in(and i didnt want to wait)
I also added the sand (just to see what it will look like) and added in a large rocks that is the same color as the background, which is also painted and fibreglassed. That rock sits on lighting defuser under the sand. I will be adding a few large silk plants as well to the decor.
The background in the pic is wet from rincing off the trimmed silicone. Its beads of water on it, thats not the texture of it.
I will update with more pics when i add water!!
If there are any questions/suggestions/coments... please post them!!