Live Rock and pH

[chshwong]

Hi Leeb,

I have an input concerning LR during hyposalinity.

I agree that, hypo will kill a lot of living creatures on LR, but I think having LR during hyposalinity is beneficial.

It STILL acts as great biological filter.
It Still acts as great PH buffer (very important during hyposalinity).
Not to mention good hiding space.

Here was my experiment concerning biological filter:
I have put 10 pounds of "Cured" LR in my 10 gallon QT.

Day 1: SG 1.022 Ammonia: Extreme (darkest green) (I poured in Ammonia, 5 drops everytime)
Day 3: Sg. 1.022 Ammonia: 0
Day 4: Sg. 1.022 Ammonia: Extreme (I poured in Ammonia again)
Day 5 Sg. 1.022 Ammonia/Nitrite: 0
Then i lowered my SG down to 1.008 all at once. And poured in Ammonia again, -> Ammonia: Extreme with SG at 1.008 now.
Day 6 SG. 1.008 Ammonia/Nitrite: 0
I poured in Ammonia again, -> sg 1.008 ammonia: extreme
Day 7 SG. 1.008 Ammonia/Nitrite: 0
------ Success, the biological survived the sudden large salinity drop
------ I haven't used baking soda all the way, and the PH stayed at 8.4
Then i wanted to test the other way, so I bumped the Salinity up to 1.023 all at once, and poured in Ammonia -> SG 1.023 Ammonia: extreme
Day 8: SG 1.023 Ammonia: Slight, not totally gone
Day 9: SG: 1.023 Ammonia/Nitrite: 0

From the experiment, I'm confident to say that, having cycled live rocks during hyposalnity treatment is beneficial. Good bilogical filter, and good PH buffer, good home environment.
I did it in an extreme way, sudden drop and sudden rise. With fish in there, I would have done it slowly which would be even easier on the salinity and ph, if the drop/rise really mattered at all.

Hope to hear your opinion on this.
Thanks

[leebca]

Since all live rock is different, there is no way to have a standard recommendation regarding it. Thus, it isn't worth the risk to have/use it. The bacterial will grow on a sponge or any surface. pH control isn't of great importance regarding the rock, since it really doesn't perform this function. The water changes will negate any effect the rock could possibly have in this regard. Keep in mind that the concept that substrate helps control pH is a myth, not fact. Likewise, rock doesn't control pH.

I appreciate your efforts, but a sick fish should not have to contend with any other stressor.

[chshwong]

Hey Leeb,

Now you've really surprised me by saying Live Rocks don't control PH. My Main and 2 quarantine tank are totally buffered by my live rocks, (in addition to crushed corals for main tank only), nothing else.
When I do weekly water change, I don't add any PH buffer, and my PH remain at 8.2-8.4.
Any source you search would tell you PH maintains PH by release of calcium. How did you get this idea/info? Cause this worries me as I have been depending on them.

As for the beneficial bacterias, the LR are just a place for the bacteria to reside. My experiment was just to show that the bacteria could live through the hypo shock. Whether it's a LR, or sponge, the same concept should apply correct?

Thanks!

[leebca]

I moved this part of the thread into its own thread on the subject at hand.

LR does not control pH. You can believe what you will but you should read up on the chemistry. pH is NOT controlled by Calcium nor is it controlled by calcareous rock. pH is controlled by the pH buffering ability of the water. The pH buffering ability of the water is controlled by three components: Alkalinity (carbonates for example), calcium, and magnesium. These three do not come from rock, only some does and to a very small extent. First read these before continuing to spread this mis-information:
What is Water Quality
and the scientific paper on the subject:
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com

Of course bacteria can live through the hyposalinity shock. If you'll notice in the post on hyposalinity (Hyposalinity Treatment) I mention the bacteria in the sponge filter may stop their activity until they adjust. This is not new.

Keep thinking though. The process of hyposalinity was invented by people much smarter than me and has been used for decades. But when its used by veterinarians and professional marine aquarists, its used without substrate, live rock and with a simple biological filter.