Why is my PH so low??

[CAGE-RATTLER]

On my 100 gallon community tank (with all sorts of species) my PH has been staying real close to 6 but all my discus tanks and tap water is right at 7.2 constantly.

Now this is the only tank with gravel and lava rock and slate and driftwood ........... so i guess these factors are changing the PH??

The KH is also lower in this tank too.

[oodi]

Hi Cage,

I don't know about the other stuff, but driftwood will definitely lower the PH in a tank.

Judi

[Graham]

The natural chemical processes, (nitrification, minerialization), of the tank create acids ie: hydrogen......Remember what pH is.....This in turn drives the pH down...the KH tries to buffer it up, but as it dwindles, remember it's being used up all the time, the pH isn't being buffered and it will drop.

The drift wood is giving off tannic acid, driving the pH lower

Dig the baking soda out get the KH back up into the 70+ ppm range and the pH will come up.

Do this slowly since your down so low. Only a few fish like discus can take really low pH. Even the nitrifiers don't like being below 6.0

[Carol_Roberts]

High bioload (food, feces, plants) will cause the pH to drop for the same reasons above.

[pcsb23]

Also fewer water changes will.

[Graham]

Thanks Carol, I should have mentioned that the more fish, the more food needed , which equals more ammonia and mulm, which equals more nitrification and minerailization which equals more acid

[CAGE-RATTLER]

Only a few fish like discus can take really low pH. Even the nitrifiers don't like being below 6.0

Maybe thats why my red serpae tetras have been dieing off one at a time.

[CAGE-RATTLER]

Also fewer water changes will.

Yeah the wife is supposed to be in charge of that tank and the water changes definately arent being done enough.

I just did a 90% WC the other day and 24 hours later it was still down to 6.

Got to get on her to WC & vac more often or pull alot of deco out!

[Alight]

Yeah, Grahm said it right. The acid formed is destroying your kH and lowering your pH. I'm guessing your tap water KH is fairly low to begin with, so it doesn't take much acid to lower the pH of your tank a bunch. When you change your water, your pH may change immediately, but will snap back down in less than 24 hours. Got to do a gravel vac, clean your filters, and do a couple of back to back water changes, and use some baking soda to buffer things a bit. You should be back to a 6.6 pH pretty shortly.

For your tank remember that 2 level teaspoons of baking soda will raise your KH about 1 degree and your pH about 1 full pH point (e.g., from 6 to 7).

Al Light

[CAGE-RATTLER]

The KH in my bare bottoms are about 150 ppm and tap is about the same.

[Graham]

Remember that in this tank you have less water changes,higher bio-loads, more mulm etc it's a micro bio-system...big difference between a that and a bare bottomed glass box filled with water,,,,,

G

[traco]

So it's your wife's job ... and they are your discus?

[raglanroad]

Cage, the pH sounds good for serpae - slightly acidic. Should never be the reason for deaths.
course, not too many fish like low pH, like discus - just a very few of our tropicals come from South America..

[CAGE-RATTLER]

So it's your wife's job ... and they are your discus?

This is not a discus tank ........... it a 100 gallon community tank with a monster pleco, giant angel, black african knife, a couple goramis, a bichir eel, a couple corys and a goldfish from a carnival thats grow from 2 inches to 6 inches since its been in there ..... lol.

Now there is a couple discus (pigeons) that came with the used tank when we got it. I knew nothing about discus then and thats what got me started learning about them. They were 2 years old when we got them and heavily stunted. With heavy feeding ........ one came around pretty nicely and doesnt look to bad. The other is still a puny runt that hasnt growna bit. he also has a broken pelvic fin. He hangs by hiself all the time in the corner and to honest .... im surprised he's still alive.

The tank was bought by the wife because she had a bunch of smaller tanks and wanted to combine all fish in one tank as a show tank. Shes been keeping fish her whole life and just doesnt buy into the fact that water has to be changed frequently. To her .... a few times a year is enough.........normally only when algae gets out of hand.

The pleco keeps this tank spotless so she hardly cleans it. In fact when i 1st started coming on this site and read about daily WC's and started cleaning the tank and doing 2 WC's a week ......... she actually got pissed and said it wasnt good for the fish .

Just cant teach an old dog new tricks i guess ..... lol.

So yeah ..... its her tank and her job to take care of it but i usually do it or it will go untouched for months.

Been trying to talk her into pulling most of that gravel out or all of it and trying a thin layer of white sand.

I did put a couple of my turks in there (a few weeks ago) and thats why ive been keeping an eye on the tank. They are paired up and waiting for a home in my new fishroom that im working on.