Natural Looking Pvc Cave

[Alexp08]

So i dont know if this has been done. but i wanted a natural looking cave for cheap. 
Went to Lowes, got some pvc. Had a torch laying around so i put two and two together. 
If you dont heat it up too much itll turn brown instead of black.
 
This is what i got
before

 
After

 
What do you guys think

 

[frapadoodle]

Can't say I have seen that method. Have seen pvc slathered in silicone and rolled in sand or gravel though.

 

[sawickib]

I wold be concerned about burnt plastic pieces getting into the water personally.

 

[Chad]

I haven't seen that one before. How will they be situated in the tank itself?

 

[BiggTexx]

I wold be concerned about burnt plastic pieces getting into the water personally.

You are on the right track, but to be more specific:
 
PVC is made of vinyl chloride (C2H3Cl) that which linked together form a polymer, there for giving you Polyvinyl Chloride. PVC is contains significant amount of chlorine and is cured during manufacturing in order to 'seal' the pipe and prevent the release of toxins, therefor making it safe for a variety of uses.  However...
 
When you burn or melt PVC, you are breaking down the PVC which releases dioxins, specifically TCDD which is carbon, hydrogen, oxygen, and chlorine (C12H4Cl4O2).
 
If you are keen are using this in your tank (I admit, it does look cool), I would make sure to thoroughly rinse the finished product, then soak in a bucket for no less than a week, checking chlorine levels regularly.  If it was me, I would not chance it at all.
 
Fun fact:  Agent Orange (herbicide used during the Vietnam War) used TCDD as a primary ingredient.

 

[Alexp08]

Well i actually scrubbed it off and rinsed it. I did not know about the release of chlorine but its in there and there seem to be no problems. 

 

[BiggTexx]

Just make to sure to monitor the water parameters and keep up with routine maintenance to be on the safe side. An extra dose of Prime wouldn't hurt right now either...