I have some of that same rock in my tank. I don’t have a silicates test kit to tell you if it is an issue. I do have a nutrient problem from my source water which I am assuming is the fueling the growth of some sponges. These sponges seem to form more easily on this type of rock than the other rock.
I was told “things” seem to attach to it very easy.
Does coraline take over the rock, or can you still see the red? Im guessing with time it will completely cover it?
Coraline doesn’t seem to grow very well on it or at least that I can tell. Other nuisance algaes on the other hand have no issue whatsoever attaching to it. On a good note they do provide some nice cave type structures, which my clown had happily hosted with for a while.
See I was going to say it may leach metals, phosphates and other not wanted items and promote nuisance algaes. The fact that coraline does not grow on it would tend to make me feel its not the best to use.
hmmm…thats interesting…about how long have you had it in the tank Ian and about how many pounds would u say are in there? (specifically of this style stuff)
It’s been in my tank since I started it and was in the tank when I got it. The previous owners apparently didn’t know what algae came from our how to remove it because it was all over the tank. They claimed they had gotten the tank from someone, but anyway it was def. in their tank for a few months, other than that I can’t say for sure. Plus the 5 months my tank has been up. No idea on poundage, but about the same amount of rock you have pictured.
Its called lava rock but it is not volcanic. It is supposedly good for biological filteration but I do not know if it gives off something bad for reefs.
So basicly good for FO or FOWLR but don’t know about reef. I have a piece as well but my tank is new. Doing some research now.
BTW I removed my rock that looked like that today. Have doing some research better safe than sorry.
Thanks for the heads up that it may be a problem.
What did you come up with after the research?
basically many different types of rock look the same and are marketed under the same name, some are good some aren’t. Wet web media says to stay away unless you are will to do some chemical tests. Silicates are the big concern. “It’s possible that a “quality assurance laboratory” might be able to test the subject rock for its make-up… perhaps give you an idea of its expected solubility for specific constituents (e.g. iron). Bob Fenner”
http://www.wetwebmedia.com/AquascaFAQs.htm
GARF says "BEST CORALLINE ALGAE GROWTH - Red Lava , this low cost rock surprised everyone who tested it in their system. It recruited and grew all types of coralline algae very well. This lava has great texture and shape. " http://www.garf.org/news9p1.html
GARF also says that some is good (as above) but some can be toxic so only use tested types. http://www.garf.org/combo2.html
Since the feelings are mixed, I decided to be on the safe side. It seems like the opion is if coraline grows on it it is OK, if not what is causing it not to. I saw where it said to have it tested at a lab or do a bio assay. For me one peoce of rock is not worth the effort. That being said if someone was able to do the testing I would be willing to throw the rock (the dead one I have) in a bucket of saltwater with a powerhead and heater (lighting might be a problem) and give a water sample to someone in a few months.
Ian if I remember correctly you have a chemistry/testing background and you may know/understand better than I, but even having it sit in a bucket it might test fine but once it is exposed to the other “stuff” (waste, creatures nibbling) it could release stuff.
Hope this isn’t too confusing. Or if it is the links above will help.
MiniMomma, thanks for doing the research! I may not be putting that rock into the new tank, it may go in the FO tank.
I used a couple gallon bucket of red landscape lava rock as bio balls in my sump for a few years. Ive replaced them now with actual bioballs in my frag system sump, but the basket of red lava rock is still sitting in the sump. full of micro stars and stuff. and biofiltering.