How to cure live rock with acid for a saltwater aquarium. | Reef FAQs


(soft rock music) – Today in BRStv Reef FAQs we answer how to acid cure dry live rock
for a salt water reef tank. (upbeat music) Hi, I’m Ryan, your host of BRStv. Reef FAQs is about quick
straight to the point answers to those questions
reefers ask all the time. Today we answer a pretty common question. How do I acid cure dry live rock to remove all the undesirable organics, prior to cycling it for a reef tank? Acid cure is probably the most aggressive method of curing rock. And I’m gonna say
straight up the least safe of all the methods and
there are very few instances where I’d recommend
acid curing as necessary or even the best method for most goals. In most cases something
more targeted at removing organics, like a bleach cure,
fits most reefers needs. That said there is a
good portion of reefers who do acid cure rock and
there are some legit reasons to do it, so we will answer
three direct questions today. What is an acid cure? When is it appropriate to acid cure rock, and how to do it? Starting with what acid
curing really achieves. Many people think of acid as something that is going to directly attack or dissolve organics on the rock, but in reality an acid cure
is a pretty short period of time, that’s not likely to happen to the degree that most people think. What’s actually going to happen is the acid is going to
immediately start dissolving the surface of the calcium
carbonate base rock. So it may rid you of the organics simply by removing the top layer of the rock that the organics are attached to, but not necessarily attacking
the organics directly, or at least not rapidly enough
to be a huge contributor. So when you think acid
curing dry live rock, think there’s so much gunk
on the surface of the rock, and maybe even elements
like phosphorous bound to it that I want to remove a
layer of the rock itself and be done with it, which is obviously amongst the
most aggressive approaches. So when is an acid cure appropriate? Well I gotta say
considering the safety risks of working with acid, as well
as the mess and disposal. I’m going to say almost never. I don’t think anyone would
do it with wet live rock, there is no need to do it
with cleaned mined rock like Marco’s Reef Saver rock, and there is no reason to do it with man made rocks like real reef rock. Even with an ocean based dry rock where there’s a lot of dried
or dead organics on the rock, a bleach cure is really
cheaper, more effective, and arguably safer as well. In our BRStv Investigates
episode the bleach cure did preform better than the acid cure at removing organics. The only real instance
where I would personally perform an acid cure
is used rock which has been in a failed tank
which is often overrun with algae and organics and
potential pollutants and pests and may even have bound up phosphate. In that case, just dissolving a layer of the rock might be wise. Then after a thorough rinse,
some reefers may continue that process with a follow-up
bleach cure as well. In fact that combo did
produce the best results in our investigates episode. Okay, so all that said you decided to perform an acid cure,
here are the six steps. Step one is consider safety. If you don’t already know
proper safety techniques and procedures for
dealing with strong acids, skip this project. Acid can burn you or blind you or anyone near you as
well as damage property. The benefits versus other
methods are not worth the risk for the amount of time to
learn how to do this safely. At the most basic level
you absolutely need proper arm length gloves, appropriate
ventilator, eye protection, and appropriate attire. You also need to do this outside,
not in basement or garage, but outside where the gases
can dissipate quickly. There’s a good chance the
container may overflow as well, which will make a mess and
damage the surrounding area. So in relation to that I would lay down some thick plastic over the area, as well as keep a few boxes
of acid neutralizer around, like baking soda. But last safety tip here I promise, simply put this video is not
designed to be the sole source of information on chemical safety. There are all kinds of
safety issues you should consider which are absolutely
unique to your scenario. You should research them, if you don’t feel
confident or comfortable, just skip this project. There are safer ways to
achieve similar goals. Okay, step two, find a
container which can hold all your rock, bring it
outside and fill it with water. In most cases it will likely be something like a Brute trash can. Most reefers used purified RODI water, but in this case tap
water’s probably also fine. Step three, once you have it
partially filled with water add your muriatic acid. Something you can pick up
at most hardware stores. The unofficial, but
general, recommendation by most reefers is to make a
solution of 10 gallons of water to one gallon of muriatic acid. I’ll say we tested both 10:1
and 20:1 in BRStv Investigates, we found 20:1 was the more
appropriate ratio for our needs. The thing to consider here
is isn’t really a ratio water to acid, but more so
a ratio of acid to rock. I mean the water really
isn’t doing much more other than making the process easier and safer. The rock is essentially
buffering the acid, and the more rock you add,
the more acid you need. In the case of our
experiment the 10:1 water to muriatic acid ratio
dissolved 25% of the rock, as measured by weight in just 15 minutes. Most reefers are probably
not gonna be happy with losing a full quarter of the rock and having it get dissolved like that. We also tested the 20 gallons of water to one gallon of muriatic acid
with our 15 pounds of rock, and only lost 12% of the rock, which seemed more appropriate
for the goal of dissolving just the surface layer of the rock. So you will have to keep this in mind, it isn’t an exact science, this is a hobby and most of
what the hobby knows is based on sharing personal anecdotal experiences. So I would read up or
watch some others personal experiences as well as their approach. There just isn’t a rock solid
agreed upon acid to water or acid to rock ratio. And it probably changes between
rock types and densities. That said, based on our
experiences, for myself, I would personally use a 20:1
water to muriatic acid ratio. Also based on results from
our investigate video, maintain a 20:1 ratio for safety reasons. I think another way to
think of that is a gallon of muriatic acid diluted
in 20 gallons of water to 15 pounds of rock. Keep in mind you could always
add more acid but not less. The last bit of it is when
diluting the acid make sure the water is in
the storage bin first, and then you add the acid to
the water and not the reverse. Adding water to acid can cause all kinds of dangerous reactions as well as splash concentrated
solution much easier. For this project and the
materials that we are working with always water first, then acid. Okay, step four, make
sure you are still wearing your safety gear and lower
your rock into the container, it will immediately start to foam. There is a very good chance that it will foam over the sides. That foam can damage
your driveway or lawns, so make sure that you have
some thick plastic down and a few boxes of baking soda around to neutralize it if needed. Step five, wait 15 minutes
and let the acid do it’s work, and then dump in a bunch of
baking soda to neutralize the reaction and stop it
from dissolving more rock. How much baking soda will depend
on how much acid you used. Then as a last step, or step six, move the rock into a bin
and rinse it thoroughly with a few different
rounds of fresh water. I might even add a box of
baking soda the first fresh water rinse just to be sure. At that point, once you’re
confident the rock has been thoroughly rinsed, let it
dry out and either bleach or natural cure the rest of the organics, or potentially just start the cycle. I’d say in our experiments
the acid cure followed by the thorough rinse and
then bleach cure produce the best overall results. So, for the last time
today we wanted to share this information because
reefers want to see the entire picture, weigh the benefits versus the challenges for themselves, but unless you are dealing with an issue that can’t be handled another way, I’d just skip acid curing all together. It has safety risks, damage
to your property risks, and it’s also a mess. If you are interested in
the bleach curing method, there it is, and the longer
more natural cure method sounds like your speed there it is, and that little box over
here has every video that we have ever done on rock. Curing, aquascaping, how much cycling, so it might be worth checking out. See you in the next episode of BRStv.

Comments 3

  • I wouldn't bother doing this. Bleach or hydrogen peroxide is still way better. I advocate using bleach it will make soluble nitrates, phosphates, and some metals. That will rinse out. I have done it both ways. CaCO3 + 3Hcl + 2H2O –> CaCl2+ CL + CO2 + 5H2O. (for example) It does generate free chlorine gas if it is not a balanced reaction! As well and loads of other lethal gasses. Very bad! Better hold your breath and close your eyes.

  • Ha ha “Rock solid result “

  • I wanted to acid/bleach cure my rock. But I used vinegar instead of muriatic acid. The vinegar took longer than the acid, 2 weeks in a 10/1 ratio, but I really liked the results. And no harsh chemicals or gases.

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