Woops dkh & Kent Superbuffer

[Aquattro]

Justin, pH drops because of the introduction of an acid. Acid can come from CO2 (carbonic acid), decaying matter (hummic and tannic acids) and animal wastes (ammonia). Nitric acid is also a product of nitrification, so in reality, your pH is constantly dropping. What you have in your favor is alkalinity; alkalinity buffers (hence the term buffer for alk products) the drop in pH by (very simply) donating an OH (hydroxide) molecule which binds with a h+(which is an acid) and effectively neutralizing it. The reason we as aquarists keep our alk so much higher than natural seawater is because we have so much more acid to "buffer".
So when you have a high alk, you tend to have a more stable pH. Of course if you have a high CO2 concentration in your home, or you spill vinegar in your tank, you may still see a drop in pH. Simple, huh?

[Justin]

Brad,

I understand what your saying, but it does not explain why in 24 hours I had a 0.2 drop in ph despite high alkalinity. Then I added buffer, and it dropped even more. I understand why I have calcium perciptation on my galss, but it still does not explain why my pH was dropping .2 a day. I have found tons of information on how the alk/ca relationship works, and understand that as well. I also keep african cichlids (tropheus) and am familiar with maintaining a high ph/dKH. Never in any of those tanks have I ever had a sharp drop in pH. It's really weird. The tank was plugging along just fine, I didn't add anything, or change anything and all of a sudden it started falling off huge. It's not a high co2 in my house thing because I have other tanks in my room as well, and they do fine. I am also very familiar with the carbonic acid cycle, and all my ph measurements were taken at night, before the lights went out. When pH is at its highest. Also, there is very little in the tank as far a co2 producing things go. I am baffled. Any ideas?

[Aquattro]

Justin, I believe the buffers dropped the pH over the short term, but I'll have to dig to find out exactly why.

[Justin]

I was just reading a million and a half posts ect, and on the topic of Nitric acid, I have one eel, about 5" long, 2 cleaner shrimp, 2 hermit crabs, 5 zerba nerite snails and some snails that came on the live rock. I have a 48gallon tank, with 28 lbs of premium fiji live rock that has been in a tank since late fall. I am also running a Rena Filstar Xp2 eternal canister filter rated for a 75g tank. The filter was established on a tank before I used it on mine. I cleaned it really good before I used it without destroying the bacteria in the biological media. My ammonia, nitrite and nitrate are all at zero. I have no skimmer, and bought an overflow box I was going to put the intake for the filter into, then run a skimmer inline with the output of the filter. I am going to go get a skimmer at Ocean on Sunday.


I just prepared 26gallons of salt, it is 1.025 sg, 8.3 pH, alk 11. Temp is one degree farenhiet out of my tank. What I am thinking about doing is putting everything into the garbage can, ripping the tank down, cleaning it to hell and putting it back together. I would obivously age another garbage can of water to give me roughly 50gallon of water ready to go when I pulled it down. I will set up the other bucket today, and rip the tank down Friday I guess.... If I decided to go that way.

[Aquattro]

Wow, a guy named foreverlearning has the exact same problem on RC
As Randy mentioned to him, pH will drop slightly with the addition of a bicarb based buffer. I've asked Randy to explain why.

[Justin]

That's me! I did add the bicarb and that lowered the pH. That is when I went and got Kent superbuffer dKh and that only made things worse.

[Aquattro]

Justin, you can do that, but remember, you don't need to let the water wiat days.
Also, and this is just my opinion, you might sell the canister filter and buy more rock with the money. The canister will promote nitrates which your rock has to work add reducing.

[Justin]

I was planning on turfing the filter when I got enough rock in there to do the job. I was also planning on putting a sump on there, or possibly a refigium, but that is more something I will do over the summer. My goal with this tank right now is to do some centrophyge, and I do think they will rip up the rock good, so I am not too too anxious to turf the filter yet. I am rethinking this whole idea tho in light of all this madness tho :x

[Justin]

How come the water does not need to wait? I have reqd a few books and all of them say to let the water age before you use it. That's what I hear a lot as well. Recently I hav read The consiencious Marine Aquarist, Natural Reef Aquariums(Tullock) and Corals by Borneman. Everywhere says let it sit before you use it. Is there some special circumstance here? Thanks for everything Brad!

[Aquattro]

Justin, that is "old knowledge" that has been disproved. Craig Bingman has an article on mixing salt....I'll dig it up. Can you tell me where in Eric's book it says that? I'm surprised he would......