29gal *update* 'Big Problem' still but some Good news also!

[RoK]

I checked the pH with 2 different test kits. Aquarium Pharmaceuticals and some junior pH test kit. I tested with the AP multiple times, kept showing very low pH. Both were showing 6.0 but I think it may be lower because that's the lowest the test kit has.
I've heard of something called a pH crash and I think that's what has happened. My tap water is very soft and the KH is always low which what I've heard can fluctuate the pH.
I just did a search and found this on a website: "KH determines on how stable your pH will be and is therefore very important.

Picture this: carbonate ions bond with hydrogen ions (which is your pH). The more bonding the higher the pH. Lesser carbonate ions results in a drop of pH.

KH of 70 ppm and less, will initiate the pH crash."
The water is definitely below 70 ppm, I think it may be in the 20-30 range.

I did do one thing that I haven't before, I used a product called "Cycle". I thought it would help to get the mini-cycle over with sooner. Do you think it could have had something to do with what has happened?
I did not use any pH up or down chemicals. I may have used a little more dechlor than I needed to though.

 

[Jchillin]

I'm just as baffled as you are. I still don't see where anything that you did would contribute to it. The cycle product nor the dechlor should not have done anything.

Picture this: carbonate ions bond with hydrogen ions (which is your pH). The more bonding the higher the pH. Lesser carbonate ions results in a drop of pH.

A definition of altered buffering properties. The question is: What/how did this occur?

Since this has not occurred in your other tanks, only the new one...how did it happen?

Have you tried testing the ph of your tap after sitting out overnight?

 

[RoK]

Have you tried testing the ph of your tap after sitting out overnight?

Yes I did, the pH is 7.1.
I do not know what could have happened to result in this. I'm going to try using a little bit of CC in the filter and see if it helps.

 

[RoK]

A Good Update!
I added some CC to the filter and after about 4-5 hours the pH has gone up to about 6.4. I know it's not good to have big changes in pH in a little bit of time but I am monitoring it and will take out some of the CC if I have to.
All the gouramis still look happy and healthy, no signs of disease or stress. There is a little aquarium salt to help with the stress. These guys are pretty darn hardy!
2 of the fish are being a little aggressive with each other but no marks have been left or anything. I've decided to bring these 2 (and the female in the 20 gal) to the pet store and keep the non-aggressive one.

Ammonia is gone in both tanks also.

 

[Jchillin]

That is good to hear. You won't believe this but the same thing just happened in my 30gal. For months, I would get low 7's, never lower than 7. Yesterday's result..6.5.

Now I'm confused (literally). I don't know if it's a sympathy pang or what. I tested three times...including my 75gal. 6.5 each time. Tap, 7.2. Nothing has been altered in the 30gal for several weeks.

Doh!

 

[mattrox]

If I get a pH drop, I do a pwc straight away. I think pH drops are dur to a build up of soluabvle organic compounds that break down into simple organic acids. Humic acid from the break down of leaves comes to mind, but I am sure there are other products which occur.

All I know is that when my pH crashes a good 50% pwc and gravel vac helps..... but the gravel vac is not such a great idea if cycling is occuring.

I am always in 2 minds about this (pH crash causing a mini cycle)....detritus in the gravel is breaking down and this is what I think causes the pH crash....vac the gravel and get rid of the bacteria that is establishing in a cycle...or...no gravel vac and leave the detruitus there and the pH remains low and hinders bacterial growth?

 

[RoK]

The mini-cycle in the tank is done, thanks for the info mattrox. Kudos to you!

 

[RoK]

pH back up to 7.0 now and seems to be staying there! Fish are still healthy and no signs of stress. I decided I will be bringing 2, maybe 3 to a LPS. I will be putting my dwarf gourami in there so I want to get rid of the aggressive ones. I will try leaving the gold that doesn't seem to be aggressive and see how him and the dwarf get along.