Is there a "right way" to prepare rocks for a FW t

[targaboy78]

I'm in the process of setting up a new 30g FW tank.

I found some rocks at a river near my home. I have washed them, scrubbed them, soaked them in a 10% bleach solution and then thoroughly rinsed them off.

I have a spare 15g that I am cycling, so when my 30g is ready, I will transfer the gravel, plants, driftwood, filter, some of the water, etc...

I placed several of the rocks into the 15g to see if they change the water chemistry. The rocks have been in there for 6 days and the results are:

These readings stayed the same;
Ca was 0 now 0
NO3 was <.5 now <.5 mg/L
NH3 was 0 now 0
GH was 20 now 20 mg/L
NO2 was 0 now 0
Fe was 0 now 0
Fe (chelated) was 0 now 0

However, these readings have changed;
PO4 was 0.5 now 0.25 mg/L
pH was 7.2 now 7.0
KH was 10 now 30 mg/L

Should the changed readings concern me?

I read something about coating the rocks in an epoxy or some other sort of plastic-type "coating".

Can anyone recommend a resin or epoxy that is aquarium safe?
or should abandon this rock project?

Any advice would be appreciated.

 

[Guest]

Well, what do you want to put in this tank? Thats what the real question is to me. Considering the slight ph drop, and the kh increase, you could have some limestone there, but that doesn't have to be a bad thing. Depending on what you want to keep, it could even be good!

I don't like changing natural materials much, so I'm sure not the right guy to recommend any epoxies or anything.

 

[targaboy78]

Thanks for the input corvuscorax, I'm thinking about a typical community tank. Some small schooling fish, maybe danios or tetras, and miscellaneous compatible species.

I'm thinking of keeping the rocks in the 15g and retesting weekly. If the pH keeps dropping or the KH keeps increasing, I think I'll abort this test.

However, if it stabilizes, I'll look for fish that prefer those particular parameters.

Is there other materials or substances, that would be harmful to fish, that I should be testing for?

 

[loganj]

Rocks

You can put some vinegar on the rock and see if it fizzes. If it does, the rock probably has some limestone and may not be suitable for the kind of tank you are talking about. You might try checking the local landscaping retailers for rock that doesn't have the limestone content. I have always been told, although I have never put it to the test, that if the vinegar doesn't fizz, the rock is OK for a freshwater tank. I know we have some rock at the store that is inert and safe for any tank, but I can't remember what it is to save my life. I suspect that your testing will tell the story soon though...pretty good approach IMO.
Logan J

 

[nikki]

rocks

I completely agree with damsel. I've done it myself and it works. the vinegar is quite good to show you if there's limestone, in which case you should either get rid of the rocks or recover them with some resin. If there's no limestone, no problem.

 

[Grant R]

Obviously collecting you're own rocks & using them is fun & of course, saves money. I tend to find personally though, that rocks and wood from aquarium specialists are much more fun and suited to an aquarium.
Best of all, the fish don't know the difference anyway

 

[CRaZeeeBiTcHisH]

limestone may NOT be a bad thing depending on your fishee inhabitants, but just because something is leeching and you aren't sure what , i would coat them or abandon them.......there is some aquarium safe epoxy, but i have never used it and i can't recall the name of it.....try a search on google groups for it....think that is where i saw it....