Using perlite /sponge rock

[Jcmccord]

Hey all!
I am looking for an alternative rock thats a little cheaper than buying cured live rock. I purchased a used tank thats been up for 10 years, but it does not have enough live rock in it. I went to the bulk rock store in town and they have something called sponge rock or perlite. I did some research on perlite, but could not find anywhere that it can or can't be used in tanks as eventual live rock. I would like to put it in with my live rock because it is very porous, light weight, and cheap. I just am not sure it will be reef safe and was wanting to know if anyone has used it or know if its worth trying. I appreciate any kind of help with this. Thanks!!

 

[OodleyBoodely]

Should be safe. I used perlite to make my live rock and it does make a great rock. Perlite is a volcanic glass and is reef safe based on what I've read of others using it). My own is finished curing and waiting for me to get the tank running.

 

[Jcmccord]

How long did you let yours cure? And by curing I put it in a bucket with my saltwater and some water movement and do changes on that water? Also is it bad for me to clean it with saltwater and put it directly into my tank, if I mix it in with the live rock that I already have?

 

[OodleyBoodely]

You need to cure it befor it comes in contact with anything live! The cure time will depend on type of cement used. I just used regular cement that does take more time to cure, but, I've read that some are using a marine grade or quick curing cement that reduces the cure time considerably. I took a long time on mine and wasn't in a hurrry (due to not being ready to use it right away), but, I left it soaking in fw for about 2months, then changed water, waited about one week and tested for ph. PH was about 8.6. so, refilled with saltwater and let set with a powerhead until use...still waiting to use it...soon now! Cure it in a tub...not in tank...because the cement will leach out alkalie solids that will form a crust on the water surface and all container surfaces. You can do more frequent waterchanges than I do, but, you don't have to knock yourself out doing frequent changes, either like some people do. The most important thing is to give it enough time to cure, then change water once or twice before using to be sure the ph is stable.

 

[Jcmccord]

oo ok. So the perlite you are talking about is the stuff you make your own rock with. I actually went to the landscaping store and purchased a rock called sponge boulder which is also called perlite rock. I have let it sit in FW for a few days now, but since this is a rock that has never seen water and never been treated do I need to cure it in saltwater? I am thinking about pressure spraying the rock because I am getting a little bit of it falling off when submerged in the water for an extended period of time. I plan to just keep testing the PH of the water to make sure it does not change, but other than that I wouldn't think it would need cured. Opinions? :crazy1:

 

[OodleyBoodely]

I wouldn't worry about curing in saltwater. Just freshwater will work. Once it tests good on ph, you CAN soak in saltwater with a little natural live rock to seed it before putting in your tank, but, assuming the rock is ok, that is just an optional step, imo. Can you post a pic of that rock? I'd like to see what it looks like. do they state what all is used in making it? If it is just perlite and cement it should be ok to use after it is cured.

 

[Jcmccord]

They did not say what it was made out of but I did some research on it and its actually made from volcanic rock. This is what I found "Sponge rock - a.k.a. perlite - is a volcanic glass. It is heated, which causes the dissolved gases to expand and puff up the glass into a foam, which is what we see." Here is a picture of it. I had some problems with a muddy red material messing up the water, but after sitting for a few days the water is clear. I figured it was worth a try at $0.20/pound.

 

[ssmallville]

Hey guys. I realized I'm a noob to this forum and reef keeping in general and that this is my first post, but I wanted to weigh in on this. Keep in mind that I've all but memorized this entire forum before deciding to dive into saltwater. I setup my tank about 6 months ago and also used "sponge rock" I got at a local rock yard due to live rock at my LFS being $7.99/lb. So here's the deal. This stuff is amazing. I paid a whopping 29 cents a pound and it looks amazing. I also stopped and pressure washed it on my way home being careful to run the sprayer for about 5 minutes to make sure all the soap was out of the line. Then when I got home I soaked for 2 days to let silt and sand settle out and pressure washed again. (better safe than sorry) I then filled my tank with saltwater and cycled my tank and rock at the same time. After about 3 weeks I was 0 ammonia, 0 nitrates, 0 nitrites, and 8.1 ph. Added some fish and 5 months later its still perfect readings with corals and all. So the bottom line is, save the bucks and use this stuff. I'm coming to realize that there is always "something else" you can spend your savings on.

 

[ssmallville]

Another quick note... this stuff if fairly easy to "sculpt" into sizable pieces. I just used a claw hammer to break it where i wanted it to. Oh and this stuff is so airy that my damsels and chromies can swim thru the holes in the individual rocks like there little tunnels, and my anenomes also love this stuff.