my alkaline water is acidic x.x

ToddnBecka · Post by **ToddnBecka** » Mon Oct 02, 2006 9:03 am

Bacteria produce nitrite, which makes the water acidic. The bacteria themselves don't make it acidic, it's actually the chemical reaction from the nitrite. It's pretty much splitting hairs on details, but you could just as well say the decaying matter makes the water acidic, or the critters and/or plants that produce the matter to begin with. Each contibutes something to the chain of events that results in nitrite.

Post by **Mustafa** » Mon Oct 02, 2006 9:27 am

Badflash...you might want to re-read my previous post. The answers to your questions are all there. Here some "highlights":

"Unfortunately the critters are not the bacteria. The critters are critters, such as shrimp, that produce nitrogen compounds, which then turns up as nitric acid after bacteria turn ammonia and nitrite into nitrate. Yes, bacteria make the nitrate, and so in a sense "produce" acids (as a byproduct), but they don't regulate anything as you implied."

The main issue is not who produces acid or not..the main issue is if bacteria "regulate" the ph level for themselves. And the answer is they do not. Here another highlight:

"If you never make water changes and keep feeding your shrimp, your bacteria will keep making more nitrate...and if nothing eats up the nitrate or neutralizes it (i.e. alkalinity), your ph will keep dropping....I've seen it happen...no regulation happening there."

To make things easier just think of the bacteria as little processing machines...in the case of the filter bacteria ammonia goes in, and after various bacteria do their work, nitrate, and nitric acid, comes out. They don't deliberately produce acid to regulate their environment. Think of the nitrate and acid as bacteria "poop" and "pee."

JohnPaul · Post by **JohnPaul** » Mon Oct 02, 2006 2:54 pm

Just wanted to thank everyone for the crushed coral suggestion; I have a pouch of it suspended in the water right next to the sponge filter, and after only about 24 hours in place, it has already raised my pH from 6.0 to 7.0.

It's a bit of an eyesore, but for now my #1 priority is getting the water where it needs to be, after that I'll figure out a way to make it look a little less distracting, maybe by trying to get some taller plants to put in that corner.

ToddnBecka · Post by **ToddnBecka** » Mon Oct 02, 2006 3:51 pm

You could place the pouch under the sponge filter, or replace it with several seashells if that would be more visually appealing. I'd leave it there until the pH stabilizes though, crushed coral has more surface area than a few seashells. Give it about a week to allow the water to become saturated with carbonates, then monitor the pH and KH after swapping it out. (Provided you choose to.)
I mixed some w/black gravel for the substrate in my tank, have been thinking about doing the next tank half coral/half gravel, neatly divided in the middle.

Alternating squares (like a checkerboard) would be really neat, but not very practical to maintain.

badflash · Post by **badflash** » Mon Oct 02, 2006 4:21 pm

ToddnBecka wrote:have been thinking about doing the next tank half coral/half gravel, neatly divided in the middle. Alternating squares (like a checkerboard) would be really neat, but not very practical to maintain.

I tried that with one of my undergravel systems and the tank ended up at around 8.5 pH. This hasn't been an issue with my pond that has about 20# of coral sand but no under gravel filter. I'm not real sure why the difference, but there it is. Great for snails, but sucks at shrimp.

Mustafa- Thanks for pointing out what I missed. It was getting late and my eyes were crossing. I think I need to get a new nitrate test kit. Even when my pH is dropping I never measure any above about .5 ppm.

ToddnBecka · Post by **ToddnBecka** » Mon Oct 02, 2006 5:05 pm

The pH was 8.5? Sounds more like aragonite than crushed coral. My tank is 7.6 w/the mixed coral/gravel, loads of live plants, and a few hundred shrimp and snails. Also 3 mexican dwarf cray's, but they don't make much difference overall.

Post by **Mustafa** » Mon Oct 02, 2006 5:52 pm

badflash wrote:Even when my pH is dropping I never measure any above about .5 ppm.

Remember..nitric acid is not the only contributor to a ph drop...phosphoric acid (from phosphate in the food) and organic acids (such as humic acids) from decaying materials in your gravel and filters can be a factor, too. That's part of the reason why some "old water" tanks with very few water changes have a yellowish color to the water.

badflash · Post by **badflash** » Mon Oct 02, 2006 6:18 pm

Mustafa wrote:Remember..nitric acid is not the only contributor to a ph drop...phosphoric acid (from phosphate in the food) and organic acids (such as humic acids) from decaying materials in your gravel and filters can be a factor, too. That's part of the reason why some "old water" tanks with very few water changes have a yellowish color to the water.

I test for phosphates and they are negative too. Are there any reliable tests for the others?

I guess I shouldn't worry as I do weekly 50% water changes like a religion. My shrimp & crays are doing fine. At this point I guess it is an art & not a science for me. I know what to do to have lots of shrimp & other inverts. I just don't know why. I hold my mouth just so as I add the water conditioner and stand on my left foot...

So explain to me why I can "dial in" the pH I want using acid. What is it the locks in in after a few weeks?

Post by **Mustafa** » Mon Oct 02, 2006 6:28 pm

badflash wrote: So explain to me why I can "dial in" the pH I want using acid. What is it the locks in in after a few weeks?

As I said before...you run out of alkalinity buffers in the water. The acid "eats it up" until there is none or very little left. If you notice, in the beginning the ph value will come back to a slightly lower ph value than the original value after adding acid...until you reach your desired ph value. That's because every time you neutralize more and more alkalinity.

badflash · Post by **badflash** » Mon Oct 02, 2006 6:32 pm

But that doesn't explain why it stays there with no more acid week after week when I do water changes.

Post by **Mustafa** » Mon Oct 02, 2006 6:35 pm

Aren't you adding RO water? If so...then there's your answer. If you're adding tap water then your results are way out of the ordinary unless you added so much acid that the acid itself is buffering the water. In my tanks water changes with tap water always increase the ph due to the alkalinity introduced.

badflash · Post by **badflash** » Mon Oct 02, 2006 7:31 pm

No, I am adding hard alkaline water to all but my one acidic tank. My latest is re-alignment of my 40 gallon breeder. Straight conditioned tap water. Pea gravel substraight, under gravel filter, handfull of coral in the gravel. pH started at 8.5, I corrected to 7.0 with acid. It bounced back several cycles, each time I corrected to 7.0. After two weeks it steadied out at 7.5. After the latest water change it is still there. Looks like something is buffering it, but if it isn't the bacteria, I haven't a clue. This was an established tank. I just did a 100% water change and churned the gravel & cleaned out the under gravel filter. No chemicals added.

Post by **Mustafa** » Mon Oct 02, 2006 7:45 pm

As I said...acids can buffer the water. When I had some higher than usual nitrates in one of my acidic tanks even 50% water changes with alkaline would not bring the ph above 7 (or anywhere near it)...it would go up a little but drop again. The nitric acid was buffering....once I got rid of all the nitrate the problem disappeared. Organic acids can buffer too...so that might explain your situation.

Bacteria would have to almost communicate with each other for all of them to agree on producing a certain amount of acid...

This kind of "communal action" has *never* been reported anywhere.