Cleaning grow rocks

[GpsFrontier]

I have tried to clean my grow rocks using a diluted bleach water solution and brushed them around with a big brush. There is still a white lime looking residue on some of them that doesn't seem to come off. Just wondering if anyone knows a good way to clean this off using stuff found around the house?

[KevinL]

I used a heavy bleach solution to wash my Hydrotom clay beads, then rinse like crazy and they seem fine. But, I also have only used distilled water in my setups thus far and haven't really had any white residue to deal with. I know if I used my Well water I would as everything in my house gets a white buildup.
I would suggest CLR, but I don't think that would be safe in the long run.
I have heard of people baking their beads or even doing it in the B.B.Q. because they weren't really happy with the smell. Not sure if that would help with your issue either, but might be worth a try with a small mount of them.

[txice]

Just out of curiosity are we talking about this "white residue" being more like hard water stains or something...or are we perhaps looking at more like a salt residue/build up from the nutrients?

If it's the later you could perhaps try using an organic nutrient instead as I believe the organics won't have any of the salt buildup. I don't use organic nutrients (yet anyways) and you can see I have this buildup around the lid of one of my containers where the nutrient solution gets from time to time.

[GpsFrontier]

I started this thread a long time ago and hadn't received any reply's, so I e-mailed my question to General Hydroponics a day or two later. They told me this white residue was from the salt buildup. Also that the bleach solution would sanitize the grow rocks but wont get rid of the salt buildup. They also said that the only thing that will get rid of it was the FloraKleen, I didn't know if that was just a sales pitch or not, but had nothing else to go on. I also thought about using CLR but didn't (and still don't) want to risk the plants and grow rocks on untested products because there may be chemicals that cant be washed out in these that will be toxic to the plants.

Just out of curiosity are we talking about this "white residue" being more like hard water stains or something...or are we perhaps looking at more like a salt residue/build up from the nutrients?

Although you get residue from water (especially hard water) I believe it's basically the same thing. Although with nutrients there are many more elements in it to build up, and may also be different colors depending on what elements are building up exactly. I attached the same pictures that I e-mailed to General Hydroponics with my question.

[Amigatec]

I plan to buy some FloraKleen this year also.

[GGM]

wouldn't a weak acid remove it? maybe drop a few clay pallets in a bowl of vinegar and see what happens.

[Amigatec]

That might do it, I used Fox Farms last year and had a lot of salt buildup, this year I am using GH Floranova, and have not had that problem.

[txice]

Originally Posted by GGM

wouldn't a weak acid remove it? maybe drop a few clay pallets in a bowl of vinegar and see what happens.

Probably a good bet. Looking at the data sheet for FloraKleen it has a pH of 4.0, so it's fairly acidic anyways.

[KevinL]

Originally Posted by GpsFrontier

I started this thread a long time ago and hadn't received any reply's, so

I'm slowly trying to make my way through the topics.

[Amigatec]

I just got done cleaning about 7 gallons of Hydroton. UGG. But it's cheaper than replacing it.