Do these rocks look safe?

[fyrefish]

Sorry if I'm being paranoid, I've just never used found rocks in my aquariums before. I found these rocks at a nearby fast flowing creek, since they are smooth and flat I thought they would be nice for my new tank. They have all been extensively rinsed and scrubbed with a scrubbing brush, they all passed the acid calcium test, and I mixed them around in a pot of boiling water for about 10 minutes, so they are nice and clean. A thing to note is they all have red splotches of iron in them, which is hard to avoid with Australian rocks. I know heavy metals like copper are a no go for aquariums, but is iron safe? also, a couple of the smaller rocks have parts of quartz crystal in them. I'll attach two pictures, one of all the rocks that passed the acid test fresh out of the boiling pot, and another of a rock that I accidently split open when washing. (They aren't particularly soft or brittle, I just dropped it onto hard concrete.) You can see all the iron inside this rock, which I assume would be the same in the others as they are very similar externally and from the same creek.

 

[MacZ]

Iron raises ion concentrations and as such conductivity.

In an Apistogramma tank you can completely go without rocks. Use driftwood instead.

 

[fyrefish]

I am planning on using driftwood, but I wanted to use rocks for plants like anubias and java fern, and to create caves for the fish to hide. Also, In most of the other rocks, there are only small patches of iron. I read elsewhere that as long as it's iron oxide its not harmful?

 

[MacZ]

Oh, it's not harmfulat all, wasn't thinking that direction. It's just going to mess up your water parameters.

 

[Sowah]

I wouldn’t use them in an apisto tank

 

[Mike Wise]

As a (former) minerals exploration geologist, I would say some look safe (inert) but some are questionable. I would try them in a tank with some 'sacrificial' fish before using them with fish I really cared about.

 

[anewbie]

As a (former) minerals exploration geologist, I would say some look safe (inert) but some are questionable. I would try them in a tank with some 'sacrificial' fish before using them with fish I really cared about.

How would you determine if they were detrimental to the fish long term ? I mean if they leached would the effect be immediate or could it take months to have a noticeable ill effect on the fish ?

 

[fyrefish]

I didn't end up using any of the rocks I found. I went to my lfs and found pretty big bag of nice looking river rocks for 10 bucks. Heres a pic of the tank so far, still needs plants and more hiding places.

I also made a custom spray bar using some pvc, it works pretty well. However, the tank is not running atm because the canister filter has a small leak, I'm getting some lubricant for the head o ring today.