We made our background with styrofoam and cement
First we purchased a piece of styrofoam from Home Depot it was 8 feet by 24 inches by 3 inches deep because we wanted to hide our tubes and lines background project 9.jpg background project 8.jpg
We used quickcrete quick setting cement and color
The piece of styrofoam had to be cut into 3 pieces to be assembled into the aquarium later so it was carved into the pattern as we were carving the rocks background project 2.jpg
As you can see in the picture above the 3rd section wasn't started yet but the first two were we drew a pattern of rocks and then used a plain to round the corners of the rocks you can also glue on pieces of styrofoam with Silicone sealant for a more 3d effect we chose not too. Most important with this kind of project you MUST use 100 percent pure Silicone any additives will cause death to your fish.
After we had carved out our rocks and cut the foam into the 3 pieces we then put it in our aquarium to see if it fit right since we had to cut it shorter then the 8 feet to fit our 120 Gallon aquarium. background project 4.jpg
Before we started putting on cement we layed down our cannister tubes to see where the inlet holes should be and carved out a space for them to sit and drilled holes down to them you will see them later in future photos because I can't find these pictures.
We then began layering the cement on the background the first layer was just the plain cement and looked grey you have to let each layer sit for at least 24 hours before putting on the next layer
The next layer we started adding color background project 5.jpg
We kept adding layers and though we would try some shading which doesn't really matter because after you cure the cement it changes its appearance anyway plus after months in your aquarium it looks different also when we did this we added more black and it was quite noticable so I grabbed a scrubby and and started blending this and it made the rocks look smoother also background project 10.jpg
You can also see in this picture that the inlet area is carved in at the bottom of the left hand corner.
After we were satisifed we started curing the background this is very important because for the first month the ph will rise especially the first few days the cement is in water background project 6.jpg
This picture show that the middle piece is not cured yet were as the 2 end pieces were cured we have 3 bathrooms so the smaller outside pieces were cured in a bathtub we were not using and the middle piece which was bigger was cured in a kids pool outside that we bought just for this reason so no chemicals had been in it yet since it was to wide for our tub.
After the ph rising had slowed down we siliconed the background into our fish tank make sure you silicone the ends and sides really well and we siliconed the joints where the 3 pieces met in the aquarium and painted over the seams with a thin layer on colored cement and then started filling up the aquarium and draining it for another 3 weeks making sure the ph was not rising in total the background should be in water for a month before fish are added background project 7.jpg
Our 3D background has been up and running for almost 6 months it does get algae on it and I use a brush to clean it off we also siliconed the ends so no fish can get back there we ended up purchasing the eheim extender set for our eheim cannister because we miss judged the inlet pipe and we have our outlets on the side of the tank background project 11.jpg