Just discovered pH spikes

[LisaT]

Prior to getting my discus about 10 days ago I followed suggestions to check for pH spikes in my water. I tested my tap water, filled a bucket, and then tested it 24 hours later....no change in pH.
So, I've been doing daily 50% water changes for the past week and a half. For lack of anything better to do, yesterday I decided to check my tap water vs. tank water. There was quite a difference. The tap water was approx. 7.2 and the tank water was about 7.6. I checked the tank again about an hour after the water change and the pH was about 7.4, as it was a combination of new and old water.

My discus appear to be doing great. Eating great, growing, and being social. I'm assuming that this has been going on since the first day and maybe the problem with my initial test is that I didn't agitate the water. If all seems to be going well is there any long terms danger to my fish? How much of a pH change can they handle? I'm assuming that the spike occurs gradually over the 24 hour period. I can not imagine where I'd keep a 35gal barrel as the "fish room" is so small (and I can't stand the thought of looking at an ugly barrel next to my tank... hate clutter). I did buy 10 cardinal tetras a few days that are in a quarantine tank. One has already died, I'm assuming it's due to the pH. The other 9 seem fine.

Should I continue on the way I've been? Or do I get rid of my furniture to make room for a barrel (one that I will have to disguise..lol).

[Elliots]

I am not sure how much of a pH difference between tap water and tank water is acceptable. For my fish I accept .4
At .4 or less I change about 50% of my water 3X weekly. At a higher difference I reduce the amount of my change to 20% but increase the frequency to 4-5-6X weekly. You have to see what works for you and your fish. MAKE SURE YOU CHECK YOU TANK AND CHANGE WATER EVERY TIME YOU CHANGE!!!

[Wes]

As CO2 leaves the water the ph will change. Airrating it will speed up the process. I would age especially in nothhern US ( winter water ).

[Elliots]

I live in a small apartment in NYC and I barely had room for my tank. I do not have room to age my water. My technique works well for me. In fact two weeks ago my tap water was 7.2-7.4 and today it was 6.6-6.8. Hard and fast rules do not always work. You need to look at what you are doing and think about it then see what works. My technique I am sure does not work for everyone. (I use a color chart for my pH readings that is why I give a pH range. I do not feel the need for an electric pH meter with essentially one tank.)

[LisaT]

Thanks everyone. I just use an API test kit to check the pH. Elliots,I have 2 tanks and one quarantine tank and absolutely no fancy equipment. Like you, I think that frequent small water changes are going to have to be my solution to the pH problem. Xeriod, I've never heard of winter water, but does that me I will have an easier time once winter is over? (One more reason to hate winter in the Northeast).
There was a huge pH difference in my water pH between tank and faucet (6.8 and 7.6). I did a 25% water change and it seemed to stay pretty stable. I'd rather do this twice a day if necessary than get involved in aging water.

[Wes]

winter water
http://forum.simplydiscus.com/showthread.php?110646-Air-Bubbles-In-Tap-Water

[Elliots]

Lisa, how big are your Discus? I would say if they are 4" or larger 25% once a day would be more than enough. If you are growing out smaller fish I do not know what would be good but 25% twice daily may be good.