What's better coral insert or diy back groud on tanks

I've been stuck trying to figure out wether a fake coral insert of the kids favorite cartoon characters the turtles fighting stance. Which isn't expensive it's just hmmm simple no real human touch has any one made an painted a non toxic stable 3 D background I really like the idea of cutting three inch PVC in angles in an pipe organ fashion with a bubbler on each section..with java moss all over them.

I have made rock walls for customers. Either slate, flagstone, or reef rock for the reef keepers. There's also nontoxic resin that you can use to seal anything that may be toxic and make it safe to use.

Not sure what you mean by using PVC to make a pipe organ with bubbles coming out. Are you wanting to make something that actually looks like pipe organs or is it suppose to look like something else? I've made backgrounds with bamboo poles and used a pole to replace the uplift tube of the undergravel filter for a more natural look. Just be sure to use a nontoxic marine grade potable epoxy resin. With some research online you should be able to find out if a local epoxy is safe to use even if it doesn't list it on the label.
PVC is a little too smooth for javamoss to stick to. You'll need to cut or scratch some deep grooves into it for the moss to grab hold of it well. 100-400 grit sand paper will work well. If you need java moss I have plenty to spare.

Thanks Amp for the information. Bamboo sounds great. I was thinking of the pipe organ theme with staggering the height by 2 inches with a half moon cut at the top grinding them on an emeory wheel go give it the grit texture ..Thanks again an yeah I could use some Java moss

please don't use the coral inserts! Georgia Aquarium took 100% of their inserts out because they create hydrogen sulfide pockets behind and underneath them. Most do not allow water to penetrate or flow through them. Ones with a bunch of holes in them are MUCH safer.
Just my 2cents..