Turning Dead Rock into Live Rock

[ActiveAngel]

So my wife and I are currently looking at getting our first house this upcoming summer... hopefully.

So a new house means new tanks. In preparation for this, I decided to start cleaning some dead rock. This includes curing it with acid and bleach (not together of course! Lol). And then soaking it and testing nutrients. And then, assuming all is well, adding bacteria to begin the slow process of bringing it to life.

Given that I have so much time, I’m in very little rush. But I’ve been busy, so I honestly didn’t put much time into planning. Just whipped everything together quickly. Nonetheless, I wanted to get the process started otherwise I may forget entirely.

Rocks include a lot of Pukani and Tonga, as well as some Fiji, Bali, Marco, ReefSaver, CaribSea, and various others I’ve accumulated. Rocks also come in Clean(ish) and Dirty rocks. I’m defining dirty as being excessively brown, covered in dead sponges and algae and general nastiness.

Removing the Nasties

1. I set up a bunch of plastic storage bins on the porch: Bleach, Rinse, Soak and Dechlorinator, Rinse, Citric Acid, Drying
2. For bleach, I’ve added a good-splash (maybe a cup or so) for every 5 gallons tapwater. Give a stir and add the rocks. Clean Rocks go in for 24 hours, Dirty Rocks for 48 hours.
3. Rinse
4. Soak in Tap water with dechlorinator. 24 hour minimum for all rocks... depending on my schedule and the pipeline of rocks ahead of it.
5. Rinse
6. Citric acid bath. About 1 cup of citric acid (crystals; like sugar or salt) for every 4 gallons tapwater. Give it a good stir to dissolve the acid. Add the rock. Clean Rocks go in for 1 day, dirty rocks for 1-2 days (TBD)
7. Dry the rocks

 

[ActiveAngel]

So far, results are good. I’ve only done clean rocks, mostly Tonga. Each step is doing its job. I was originally going to take measurements of everything, but as stated, it’s been busy. Nonetheless, I can take photos if requested, answer questions about what I’m doing, or listen to feedback.

 

[Adam]

For the dirty rocks I'd recommend a lot more bleach and a much longer soak. You can get the bleach for less at Home Depot in the pool section. It's 10% instead of 6% and it's a true gallon. I let the dirty stuff soak for weeks and "Shocked" it a couple times by adding more bleach. I didn't use a dechlorinator, just rinsed them real well and let them dry out in the sun.

On the citric acid, I mixed it to about 5%. Mix up the acid first then add well dried rocks into the tub. A half hour to 45 minutes is all you need on everything except the mined rock, like Marco. For that cut it to a half hour max and maybe pull it at 20 minutes. Once it stops bubbling the acid has gotten much closer to neutral anyway.

 

[ActiveAngel]

Yeah, I may take your advice on the longer and more intense bleach soak for the dirty rocks.

As for the citric acid; do you mix yours at 5% by mass or volume? I’m at 2.5% by mass... with minimal but ongoing reactions at 24 hours.

 

[Adam]

Yeah, I may take your advice on the longer and more intense bleach soak for the dirty rocks.

As for the citric acid; do you mix yours at 5% by mass or volume? I’m at 2.5% by mass... with minimal but ongoing reactions at 24 hours.

Mass because I was doing large volumes. 40 gallons in a stock trough.

@ActiveAngel I was using 50lb bags of citric acid. I was weighing myself with the bag and pouring out some and reweighing till I had the right amount. for smaller batches if you had a good kitchen scale you should be fine doing it by mass.

 

[ActiveAngel]

Mass because I was doing large volumes. 40 gallons in a stock trough.

Thanks!

Ya, I increased the bleach concentration and time length for the dirty rocks. The first 24 hours definitely wasn’t enough for them.

The citric acid is actually doing great so far, so I may keep it at 2.5% or I may double it and decrease the time. But good recommendation regardless.