3D backgrounds to me really "make" a tank. It gives just a super realistic look and really sets your tank apart from the average tank by making it unique looking. Plus I think the fish probably like it because it gives them a more nature habitat as well as gives them more places to hide and feel more secure, I see mine sitting in the crevasse's of the background very often. Let me try to take your questions one by one here that will be the easiest way to do it...
Owens Corning Foamular F-150 1 in. x 48 in. x 8 ft. Scored Squared Edge Foam $20
Right foam, but I would suggest getting the 2" thick sheet. The 2" think one will give you the means to do a background that has more "depth" to the 3D look of it. It's easier to staret with a thicker foam and carve out(remove) foam than it is to have to add foam to make it thicker in spots where you want it to come out more.
Quikrete 60 lb. Concrete Mix $2
Ditch the cement idea. People started out using cement some years ago but now a days Drylok is a MUCH better media to use for coating the background. Some of the benefits to using Drylok are
- Drylok is does not alter your PH like cement will do
- Drylok retains the details you worked so hard to create where as cement will fill in and hide the details even with light coats
- Drylok is much cleaner and easier to use
- Drylok is lighter which makes installing easier and it does not crack the way cement will over time
There are a some other benefits to using drylok but those above will give you the main points as to why it is far superior to use than cement.
Quikrete 10oz. Cement color (variety) $5-$10
You "can" still use cement tint even with Drylok if you want, but using Fusion or any spray paints that are "plastic approved" spray paints work even better and are easier to use. As long as they are paints that are for plastic then you will have no worries about leeching any toxins with them.
5 gallon bucket $3
Wont need this if you use Drylok
throw away brushes $1
Yep get around 5-6 brushes. One or two 2" wide for applying Drylok, then a few 1" wide ones for "dry brushing" the shading colors onto the background.
Blow torch or heat gun(to melt the insulation to give nice round edges) own one already but price: $10-$40
You
can use a torch but a heat gun works best if you happen to own one.
Cutting tools: razor blades, hand saw, steak knife, machete jk but anything to cut the board into shapes of your desire $3-$20 depending on choice
Pretty much anything you have on hand works. I personally use a flat screwdriver, hacksaw, and drywall scraper myself and it works perfectly with just those three items.
Straight edge $7
Yard stick, piece of 2x4, pretty much anything with an edge works for cutting the background to size.
Caulking gun $2
Silicone GE 1 window and door $5
Yes make sure to double check that you are getting the GE silicone I "window door attic" clear silicone. Because the others such as GE silicone 2, and the basement and plumbing GE versions contain mildewcide and will kill your fish. Ge Silicone I is actually the exact same think that is sold in pet shops as "Aquarium safe sealant" so make sure to get the proper one.
(Hot glue gun optional)
No need for that, the silicone will act as glue for anything you need in this project and is 100% fish safe unlike some glues.
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The process for doing it are as follows...
1- Cut the background to fit in the tank. Don't forget to allow enough room to fit in between the tanks braces on top. This may means either removing the braces and reinstalling them, or simply making the background to fit together in sections once in the tank. Plan this out ahead of time to save yourself some major headaches.
2- start carving out your background. I find a basic idea of what I want mine to look like is much better than coming up with something that I try to stick to hard and fast for the look. In other words don't be scared to change something on the fly and go with the flow. Just have a basic idea of what you want and have fun with it.
3- once you have it carved how you like then test fit it together in the tank. Easier to alter something now than once it is all coated and done
4- Apply the Drylok. I use three coats to make sure it is nice and evenly covered and I usually give it about 24 hrs between coats because it does take some time to dry.
5- Once the BG is coated in Drylok then start doing your shading work. If your are not familiar with a technique called "dry brushing" then Google it and see how it is done. The best way to add your shading colors is to spray the paint from the can onto a small plastic cup (just covering the bottom of the cup) then dip the brush in and then wipe the brush on a paper plate, then drybrush onto the back ground. It takes some practice but you will get the hang of it quickly. I also like to "smash" the brush bristols down on the table before I dry brush to give the brush more of a spread out flare effect which helps.
6- After the background is shaded with your shading colors then do the same dry brushing with some white fusion paint only going over the high spots on the background. That gives it the look of real rocks that have been worn down a bit on the edges and adds a nice natural look.
7- test fit it all again because your next step is to silicone it in the tank so now is the time to double check and triple check it fits right.
8- Coat the back side of it (backside should be unpainted/not dryloked just bare foam) coat the back side of it with GE Silicone I. To give you and idea of how much to use, it takes about 1.5-2 tubes for a 55g 4ft wide background. You don't want it coming lose so use a lot of it. After it's in then use clamps, pieces of wood wedged into the tank between the glass and BG, or anything you can to hold it firm in the tank and let it dry for at least 12 hrs before removing.
9- Let it sit for a minimum of 3 days (week is even better) so that the silicone and paints all are 100% off-gassed.
10- after waiting 3-7 days now fill it with water and drain it 2-3 times. That will help remove any particles that may be in the edges of the background or in the tank to keep them from floating around.
Now you are ready to cycle and add fish when it is cycled.
That's how I do all mine. I've done about 5-6 of them so far and currently working on a huge one for my office. Hopefully you will find the above info helpful and don;t be afraid to ask any questions you may have along the way.