View Full Version : Is this possible?? I am sooo confused!

02-21-2010, 04:04 PM
Ok, I have a 55 gal that has been up and running for 2+ years... do regular water changes and gravel vacs. Ph has usually been between 7 - 7.5ish all this time. NO new fish added and it is not overstocked. I have always had an issue with NitrAtes in this tank, but the fish seem to be OK. I can't ever seem to get them down past 40 for some reason. No unusual rocks for decor. and I just use plain natural gravel I got from the fish store for my substrate.

Well this weekend it was due for it's 2 week water change and I checked the ph before I started... it showed 6.0! The fish don't seem to be stressed and are eating well and appear healthy, but my ph has never been this low!

I keep a cory, black skirts, cardinals, black neons, platy, swordtails, and rio tetras in it so the ph while not too big an issue for the tetras, is kinda low from what I have read for the livebearers. Although they are used to quite a bit higher ph as I stated above.

I tested the GH and KH and they seem to be in the good ranges. Is this possible??? I thought the dissolved minerals in the water determined the ph. If that is true, how can my ph be so low and the GH and KH be OK??? Can someone please tell me if I am missing something and what that might be?

Would adding some Kent's R/O to the water gradually over a few days fix this issue?

02-21-2010, 04:22 PM
This is just a theory but were I live in the spring/winter the tap water has a much lower ph 7.2 as opposed to in summer/fall its 7.6-8.0.

02-21-2010, 04:23 PM
nitrates occur naturally in all tanks from fish waste being converted into ammonia to nitrites to nitrates. fish waste will lower pH, so that could be a cause. RO water wont help raise the pH, as it is absolutely pure water with nothing, so it will be exactly 7.0. people keep livebearers in community tanks with a lower pH, so i wouldnt worry too much about them stressing out.