Concrete Block in aquarium??

[absoluteincubus]

I have a 55 gallon saltwater fish only tank and i was wondering if anyone had anyone had information about putting a concrete block in the tank. My fish are getting bigger and need a bigger place to hide out. My main concern is the weight issue because the block is pretty heavy.

[Innovator]

Leach it first and test. Why not add liverock and make a cave?

[lance]

Im not sure but i have been told it releases ammonia in high amounts. A safe alternitive would be PVC tubeing. I made a square box and placed my best LR piece on it.Elevates the rock up and allows water to flow through and makes a great spot for larger fish.
Also base rock which is cheap. You can put 75 % base rock and 25% LR with no problem and less cost and less chance of unwated hitch hikers.
The cinder block doesnt sound right to me.

[melosu58]

I agree that a concrete block is not the way to go. I just saw a thing on how they make them and it was too much stuff added to them. Use BR or LR will be better.

[absoluteincubus]

Thanks for the replys. I was going to use the block because there like $2 and the perfect size for a hideout. I guess ill play it safe and not use it. The PVC sounds like a great idea though. I would like to see a picture of this if you wouldnt minde sharing Lance.

[lance]

This is a very old pic but does show it. Its covered in very nice brown and pink coralline but it hard to get a pic.

[lance]

Oh and on another note see the small hammer in the middle , look at it now and its even been fragged once.This pic is also a few months old.

[land locked]

I talked to my husband about this (he own a concrete co) He said don't do it. It will leach for years all kinds of nasty stuff (he listed them all,yawn). He suggested this foam they use in pond and aquariums it is black and you can shape it however you want we used it in our pond and it looks cool. It kinda works like spray insulation only it is safe for the aquarium. Sorry we can't remember the name but we bought it a Lowe's.

[roka64]

You can make your own with aragicrete (I think that's what it's called).