Try that front view picture again...

 

I used the Krylon plastic bonding paint inside of my aquarium to cover the acrylic and prevent my aggressive betta from constant glass surfing. Personally, I am not super paranoid about paint in tanks so long as it has a thorough drying and curing time. At least 48 hours, preferably 72+.

Since this is on styrofoam however, I can't recommend anything that will bond to the styrofoam without flaking.

 

If you watch the King of DIY's youtube video on custom decorations or backgrounds he paints them with cement. It will affect your gh and kh but cement is hard to beat when it comes to durability and natural appearance
Edit: you could use crushed up graphite as a black dye in the cement. Watch out for powdered dyes that may contain iron or copper.

Sent from my Nexus 6P using Tapatalk

 

Uaru Joey (Mullen - King of DIY) also says that Krylon is safe for aquariums.

 

My spray bars for my returns inside my tank are pvc pipe that I painted with Krylon Fusion. This is the only spray paint that I know of that can be used inside an aquarium. I have had a good experience with it so far being used with pvc. If you try it I would recommend spraying it on a scrap piece of the styrofoam to see if it melts it or not.

 

I'm pretty sure spraypaint will eat away the Styrofoam, which is the big reason all of the DIY Styrofoam backgrounds are covered with a layer of cement prior to painting. Then again, if you cement your floating islands, they won't float anymore so you would have to hang them from the top.

 

They will still float, the thin coat of cement is not near enough weight for them to sink. You are right about the paint most solvents used in paint will cause a chemical reaction breaking down the Styrofoam. I know using acrylic paint (like from a hobby store) is safe and will hold up under water for some time but if you use acrylic paint and then a non toxic sealer (I used clear Drylok) it will last an very long time.

Dan

 

Krylon Fusion is safe to use in an aquarium, but as mentioned before, may melt the styrofoam. One possible way to use it directly on the styrofoam without melting it might be to use extremely light coats of paint, just dusting the surface so that there is not much solvent to eat large holes in the foam. Just be sure to read the Fusion label for drying time between coats, as I remember it needs a week's wait if new coats are not applied within a certain timeframe. (This would also indicate a week's time to fully cure.) It does dry fairly quickly, though, so building up repeated light coats shouldn't be difficult, especially considering that any plastic-disolving solvent will disapate quickly. If you have a spare piece of styrofoam, it might be worthwhile to try the light, dusting coats until you get a good layer of paint to see if that method will work for you. Once you get a decent coat covering the styrofoam, you shouldn't have a problem with it melting, since the paint will then be bonding to itself.

Looks like a cool setup; let us know how your project proceeds?!

Olskule

 

You need to seal Styrofoam or the paint will eat it. Most PVA glues seal Styrofoam without causing it to melt. But the thin layer of cement or drylok is a good idea as well. I have used krylon and rustoleum inside my tanks for the past couple years without issue.

 

Coat them with epoxy resin with a tint added. It is neutral and will not melt the styrofoam.

 

My background is painted with tinted Drylok. It has been in the tank over 4 years now with no problems.

 

I think there is a fair amount of missing thinking on the Krylon. It is not so much that it is safer but that it is designed to stick to plastic somewhat better than most of the "rattle-can" paints. I have never used the Krylon but do use the cheap stuff. I feel it's not the paint itself but the volatile portions of the spray. When I paint things for the tank, I let it dry really well and then some more. It is somewhat like the cement for PVC and can take some time before the smell is ALL gone and then just as a kicker, I do a light bleach soak to fully ease my mind. The cheap stuff probably knocks off plastic quicker but then I'm not really happy with the durable part of any spray paint. For foam, I might try giving acrylic hobby paints a try. The water clean-up types are reasonably safe and certainly less prone to eating the foam.
I like the Avatar thinking!!
roud:

 

Hi I know this is an old thread but I have an external canister filter that comes with hideous green internal pipe work, it stands out like a soar thumb so I was thinking of painting them and thanks to this thread I think I have found the paint I need but wanted to ask if this is the paint to use or is this the wrong thing altogether ? Thanks in advance...

 

This is the same paint that I have used in my freshwater aquariums for over a year without any issues. Although not that camouflage green color, I have only used the flat black but same paint just different color.

 

Thanks for confirming the paint for me, I will be using black but just wanted to make sure it was the right brand of paint before ordering, thank you again 🙂