Quality of base rock?

[Gdbyrd]

Do you ever worry about the quality of base rock? Long story short, I have some limestone I got from a LFS. One of the pieces that hasn't gone into my tank yet, has an orange stain on it. It looks like it's a part of the rock. I just don't want to put anything in there that's going to leach something bad. Is it OK?

 

[dcantucson]

I don't think I would use it.

 

[Gdbyrd]

I don't think I would use it.

That brings up another problem because the piece I had gotten from them earlier IS in my tank. Still no livestock, but, I don't want to start building on a bad foundation. The other rock was completely clean, almost a perfect white. But this one with the stain makes me feel a little nervous.

 

[mng777777]

FYI, Limestone is a calcium carbonate and it will slowly dissolve into the water. As it dissolves, it will raise the PH. It may have only a small effect depending on how much rock you have, but it could also raise the level to a very alkaline state. Are you sure it's limestone?

 

[Gdbyrd]

Are you sure it's limestone?

Not exactly. My dad picked it up for me while he was in San Antonio. The lfs told him it was a type of limestone..You guys tell me, best photo I could get of the one in the tank already.

 

[mng777777]

Looks nice. I love the shape! I'm not even going to attempt to tell what kind of stone it is from a pic. It doesn't look porous though. Is it? If it is one solid chunk of rock I am going to have to say that you might rethink whether you want it in your tank vs traditional LR. The key to LR is that it's porous which increases its surface area exponentially. You will not have the same amount of beneficial bacteria growth with solid rock. A lot of the rock that pet stores sell is designed to be decorative and if you end up with a load of that in your tank you are going to have a tough time keeping up with your tanks bio-load

 

[Gdbyrd]

Thanks! I love the shape too. The rock is extremely porous. It's about 11lbs I think. I have another one that's 13lbs(the other one in question). I just wanted to put a piece here and there for the look of the rock and to save some money.

Should I keep it in or add the other one? Is it a bad idea to keep as a foundation for the rest of my rock?

 

[mng777777]

A good test for whether its porous enough or not is to place it in a bucket or the sink, and slowly pour RODI water over it. If the water runs immediately off the rock and down the drain, it's not porous enough. If the water disappears into the rock and leaks out the bottom, you have a winner! Those both sound pretty heavy for their apparent size. Bottom line though, is if you are using them with LR and you feel that they are porous enough, they should be ok, and they look great! Just test your water to make sure that your PH stays in range in case it is real Limestone.

 

[lilyicu]

It is good old Texas Holey rock!!!!! I love that stuff. I have a lot of it in my freshwater cichlid tank.

I also have a large amount of holey rock as base rock in my saltwater tank. It is much cheaper than the live rock. My tank has been up and running since the beginning of April and all of my holey rock is starting to turn colors. Most is a darker grey with purple and green spots.

I got the tank up and running with the holey rock and then seeded with the live rock.

If you are worried about the spot you can boil the holey rock (I don't know how big your piece is). My largest piece is over 25lbs. The ones I clean in my freshwater tank I place in a large tub from Walmart add 2 cups of bleach and cover with water. I let it sit for several hours. Then I dump everything. I fill the bucket back up with water and dechlorinator (a lot) and let it sit for several hours. Then I dump and repeat. The whole next day I leave the piece out in the sun to kill off anything else that my have been left behind.
They are close to being good as new. Most holey rock will have some slight discolorations but if you are unsure just clean it and it should be just fine.

 

[lilyicu]

BTW, the LFS down here also call it honeycomb rock.

I did a lot of research on using the holeyrock (limestone) and it seems that most people in Texas use it to seed their saltwater tanks with. Hope this helps :)

 

[Gdbyrd]

Sounds good, thanks for the help! The spot doesn't look dirty, I'm just worried about it being a metal stain. If that leeched out into the water that would really, really suck : /

 

[lilyicu]

The bleaching will help get rid of whatever is on your rock. :)

Good luck with your tank!

 

[tankedchemist]

If it's an orange stain-- and I'm assuming not something biological-- then it's just iron oxide... rust. It's a normal part of some limestone. Iron's in the blood of much of the lifestock in your tank... won't hurt anything.

by the way, if you want to know for sure if it's actually limestone or not, get some dilute hydrochloric acid (lysol toilet disinfectant has some in it) and put a bit on the stone. If it bubbles and fizzes, it's limestone.

 

[Gdbyrd]

If it's an orange stain-- and I'm assuming not something biological-- then it's just iron oxide... rust. It's a normal part of some limestone. Iron's in the blood of much of the lifestock in your tank... won't hurt anything.

by the way, if you want to know for sure if it's actually limestone or not, get some dilute hydrochloric acid (lysol toilet disinfectant has some in it) and put a bit on the stone. If it bubbles and fizzes, it's limestone.

Hey! Thanks for the tip. I'll have to give that a shot. Quick question, should I put more than one piece of this stuff in my tank? It'd total about 25lbs in my 47g tank. My only worry is the pH issue. Like lilyicu I've read a lot about people using this frequently in salt tanks, but I'd like a few more opinions.

 

[tankedchemist]

did you do the test mng suggested to find out how porous it is? That's what I would use to decide how much to put in.

 

[Gdbyrd]

did you do the test mng suggested to find out how porous it is? That's what I would use to decide how much to put in.

Well, it didn't do exactly has he suggested it should. If I drip water off onto it, it will absorb it, but some of it will run down the side(but will get absorbed there). It certainly feels like it has a rough enough surface and I'd guess it's porous. If it's better to leave it out, I'm OK having a 28$ paper weight.

 

[tankedchemist]

Then I'd probably use it, personally. Limestone is made from sea shells and saltwater components. I know that it is used in freshwater streams, where mining has caused drastic pH decreases, in order to raise the pH... however, at the ion concentrations and pH our tanks are at, the amount of limestone leaking into your water is probably going to be pretty minimal. Besides... you do enough water changes and monitor pH and alk, you'll be fine. :)

 

[Gdbyrd]

Then I'd probably use it, personally. Limestone is made from sea shells and saltwater components. I know that it is used in freshwater streams, where mining has caused drastic pH decreases, in order to raise the pH... however, at the ion concentrations and pH our tanks are at, the amount of limestone leaking into your water is probably going to be pretty minimal. Besides... you do enough water changes and monitor pH and alk, you'll be fine. :)

Sounds great! Thank you for the info. Now to restack all my rock :) By far the most enjoyabe, AND frustrating part of this hobby thus far.

 

[dcantucson]

If there's this much questioning about the rock, just leave it out. Why take any risk at all! This hobby is hard enough to wonder if a piece of rock is safe or not. Put it this way, if you use it and something happens in your tank down the road, you'll always question if the rock has/had something to do with it. You don't need the headache! Don't use the rock!!! If you do then chances are you'll take it out later; in which case it will be much harder to do that!!! DON'T USE THE ROCK!!! JMO

 

[lilyicu]

I have used about 40lbs of just holey rock in my tank and have never had an issue with the pH. Limestone will actually keep the pH in the higher range where it is supposed to be. Both cichlids and saltwater fish require a pH of at least 8 if not slightly higher (mine stays at 8.2). It will help you maintain your pH. It is not enough to make your pH too high. I have never had to use a high pH additive, the holey rock does the job for me. Texans are blessed with holey rock. I have to buy mine I am too far south, but up in San Marcos people line their driveways with it. I am so jealous :)