View Full Version : Lava Rock Good Media?

03-01-2006, 9:35 PM
I was just told by my LFS that lava rock lowers pH and is obsurd for media in a SW tank or FW? He said it lowers the pH. The store itself is reputable, but not sure about this guy. Any ideas?

03-02-2006, 12:59 AM
hey fish nerds??? somebody? anything at all would be better than nothing.
I kinda need an answer asap :look:

03-02-2006, 6:06 AM
Depends on what kind of lava rock. The Red lava rock you often see for sale at fish stores is actually a byproduct from metal smelting and is inert, which is aquarium safe. Lace Rock is a windswept volcanic rock that is also safe for aquariums.

03-02-2006, 10:32 AM
this rock is cinder (black) and it is pure lava rock from the island of Hawaii. IS that safe? pH problems?

03-02-2006, 10:38 AM
Lava rock works good, too good. I had high nitrates because of too much bio. Removed most of the lava rock, and the nitrates fell.

03-02-2006, 10:47 AM
Is that the inert Lava Rock or regular lava... because apparentlly the lava rock in LFS are treated and inert, now I'm trying to figure if real natural cinder(definition is burned and cannot be burned further) lava rock is safe for aquariums?

03-02-2006, 11:20 AM
Real cinder is not advisable. While it won't lower the pH, it may leach toxins into the tank. You can try it out in a tub of SW--test the water, soak the rock for 3-4 days, test the water again.

You really can't have too much bio-media. What you can have is too many places for solid debris to become trapped and inaccessible to larger scale cleaners, which will then increase the ammonia produced (and the nitrites, and the nitrates). But, this is because there's too much food for the bacteria, rather than because there is too much bacteria.

03-02-2006, 5:42 PM
I will test it out in a bucket... what should I actually test for?? Minerals??? Copper?? oI guess pH...

03-02-2006, 6:29 PM
One thing to keep in mind that volcanic rock can vary in composition depending on where it originated, temperature of the lava at the time of the eruption, and the rate at which the lava cooled. Because of this, there can be variations in mineral make-up from one area to another and even in lava that erupts at different times or areas of the same Volcano. I think you would be best suited to place the rock in the salt water like you said and let it go for a while and keep testing for known fish killing substances over at least a month. Iíve heard of people using Volcanic rock for fresh water fish and have not heard any issues. I would love to hear if it works, I think the black background could offer a striking contrast to the colors in SW fish!

03-02-2006, 7:37 PM
I am currently performing the experiment in a 5 gallon bucket of instant ocean SW mix with an air pump...there is about 5 oz of Cinder Lava Rock from the island of Hawaii in there. Does 3-4 days sound like a good waiting period? Maybe I will try testing it then and then at the 7day mark. I'll def get back to yall...
**** GeorgiaMan why do you have to tell me all those variables? Does this mean this experiment is obsolete for anyone else? I guess will have to see if there are any traces of any fish killer substances first. Do a basically test for ammonia, pH, nitrite, and what else??

03-02-2006, 8:42 PM
I wouldn't say obsolete, I think it is a great experiment and if it works, one that others can follow. I would test for Copper and other metal compounds that have test available. I mentioned the variables because I felt it was good for anyone to know that by just saying lava rock, does not mean that all is the same. There are so many people out there that will tell you anything to sell something whether it is true or not. I personally would like to be able to duplicate your "test". We put so much time and Money into our tanks, that mistakes can be costly as well as cost the objects of our enjoyment their lives. I continued to do research on this after I posted my last comment. I cannot find any reference of Lava rock and salt water tanks. I did this because the idea of lava peaked my interest. What I didn't even mention is the ability of some substances that can be lava to effect PH levels so I would test for PH also.

I would love to hear your results.

03-08-2006, 9:48 PM
I went to 2 different LFS and 1 said lava rock lowers pH and is not good for SW or FW unless lower pH is required... the other LFS said that it is fine for fw but not salt b/c of all the minerals in it it will leach the color of the rock. Now I've had a few ounces of lava rock in my SW tank for at least a year with no major problems and never leaching color.

Meanwhile the bucket tested as follows:
ammonia- around 3.5 (between the last and second to last on chart)
pH- 7.8 which is normal for my water
nitrites- 0
copper- 0
Also, the bucket is crystal clear.
Is it possible it started to cycle already?

IMO I think it will work just fine but I need to know for sure about the pH deal.
Oriongirl said it won't affect the pH, but she said it may leach toxins into the water, what toxins were you refering to Oriongirl??

03-08-2006, 10:25 PM
Yes, it will start to cycle immediately. Copper, heavy metals, etc. The 'lava' rock sold in stores is completely safe--I've had it in FW and SW tanks with no side effects. The concern I express is for using real lava rock, as in volcanic rock, not clean slag.

03-09-2006, 4:33 PM
I picked up a few football size chuncks up near Mt Lasson a few years ago. They were mostly red or brown. I rinsed well with the garden hose, lots of bugs came out. Then soaked in saltwater with a power head for 2 months. Aclimated some hermits and snails ( I figured heavy metals would kill them first) I saw no ill efeccts to them and added the proverbial Damsel to the mix and all was fine 6 months after picking up these rocks I added them to my tank and they are very full of life now. There is lots of Lava that flows straight into the ocean there in Hawaii and as far as I know the fish are still swimming there :shark:

03-09-2006, 5:52 PM
Thats prommising, and you make a great point, thanks... do you know if cinder would make any difference to the lava rock?