What's up with my PH?

  • We are currently upgrading MFK. thanks! -neo

V1xIII

Gambusia
MFK Member
Jul 11, 2008
314
0
16
MO
So here's the deal,

My tapwater PH when tested with an API high range liquid PH test is 7.4 dead on, which is the lowest the test goes, so for all I know it could be even lower out of the tap.

I've been fairly baffled as to why my tanks never, ever have a PH lower than 8.0, but since I recently noticed one of my tanks at around 8.3-8.4 I started becoming more concerned and wanted to figure out why.

I of course assumed it may be something in that tank that was causing the PH to rise, either plastic decoration or gravel. So I pulled a couple of the plants out, put them in a plastic bowl filled it with tapwater, and filled a plastic cup with the same water to use as a control sample.

After a couple days I tested the PH of the water in with the plants, not entirely to my surprise it's PH had risen to the lower 8's. I then tested the control water, and surprisingly it's PH was even higher than the plant water.

I then realized my test was stupid because regardless of the plastic plants being in the water, both the plant water and the control water were in plastic containers as well and ended up with higher PH. So for all I knew, all plastic made PH rise.

Once I realized my test was flawed, I put some tapwater in a GLASS and let it sit for 2 days. Remember, my tapwater has a PH of 7.4 or less out of the faucet...

So what was the PH of the tapwater that sat in a glass for 2 days untouched, and without any additives?..... 8.3

Does anyone know how that could possibly happen? And I guess more importantly what I can do about it in my tanks? According to crappy dip strips, my tapwater has very high GH and KH, so it doesn't change PH easily, except for apparently in the wrong direction for no reason.... :irked:
 
The test kits are sometimes innacurate or you make a mistake about something, for example once the test kit said my tank was 5 but then the next day 8 and none of my fish were dead.
 
Get a new test kit.
A complete "master test kit" will test everything and it's very accurate..Thats what the good lfs' use to test their tanks too.

Why r u using a "high range" ph test kit? What kind of fish u got?
 
V1xIII;2081859; said:
Does anyone know how that could possibly happen? And I guess more importantly what I can do about it in my tanks? According to crappy dip strips, my tapwater has very high GH and KH, so it doesn't change PH easily, except for apparently in the wrong direction for no reason.... :irked:

Yep, this is my water. I"ve got well water that's stored 200 ft underground. When water is stored under pressure like that there's mega amounts of undissolved CO2 (like fizz in soda). The water straight out of my tap is 7.2 pH but when I let water sit in a barrel 24 hrs with a bubbler in it to age it, the pH is 8-8.2 (although my kh and gh never change). The pH in my tanks run 8-8.2.....because it's 'aged' and the CO2 has had time to dissolve and 'let out' of the water. I belive that's what's happening with your water. Undissolved CO2 makes the pH of the water 'read' lower but once it's been aged it'll read at the correct pH. Very common occurrence. I age all water over a 50% water change for this reason. Because it can deprive the fish of oxygen if I were to do an 80-90% water change with straight tap water (because of the undissolved CO2).
Does that make sense to you? If not I'll be glad to try to explain further. You can look up "gas bubble disease" on google and find lots of articles that explain it also.
 
Yeah Ksane, that's pretty much what i've decided was causing it. Some responses on AquariaCentral said the same thing you did. http://www.aquariacentral.com/forums/showthread.php?t=162700

I knew that CO2 caused PH changes, but I was unaware that it occured in tap water like it does.

And to the other responses, my test kit is only a few months old so I doubt it's bad yet, and the reason I use high range test kits is because of the natural high PH of the tapwater here. Why would I need to test for anything below 7 when none of my tanks are ever below 8?
 
I've tried to explain that so many times to people on a certain other site and they think I'm nuts or don't believe me. I was glad to see that thread in your link and your response here. For the record you can be thankful for your hard water, at least it's super stable :-)
 
MonsterFishKeepers.com