Unexplained PH Drop

FreakIndeed

FreakIndeed

Yo yo yo!
Oct 7, 2006
233
0
0
46
Columbus, OH
Here's the deal. My tanks were established back in July (driftwood was added at that time). For all of these months my PH has always been stable right at 7 to 7.2. The PH out of the tap (even after setting) is about 7.8. I tested my tank PH today and now it is 6.6. Both tanks are exactly 6.6. Obviously my first thought was my PH test kit went bad. So I tested my tap water and it again showed as 7.8. It's a liquid test from AP and appears to be perfectly fine. I'm always on top of my water changes (40% a week). In fact I just did a water change last night which would normally raise the PH of the tank a bit until the water settles, yet today it's 6.6. Does anyone have any idea why I would experience the drop? I don't really mind the PH being 6.6, but I would like to at least know why... any ideas? The only thing that has really changed is the chlorine remover that I use when doing the water changes. I started using A.C.E. by Jungle. Could that be it?

P.S. Fish are acting just fine and the last time I tested the PH at 7.2 was about a week ago.

Thanks!!!!
 
Yes, have been testing KH and GH. KH is 3 and GH is 9. These are the same numbers I have always had even before the recent PH drop to 6.6.
 
Also forgot to mention. Ammonia 0, Nirtite 0, and Nirtate 7 in both tanks. One has gravel that is vacuumed each week with water change and the other has sand that is cleaned and stirred each week with water change.
 
Well-established tanks always go acidic over time because acid is one of the by-products of the nitrifying bacterial action.

However, if this is the relatively stable pH that your tanks will keep, it's a blessing. All of the fish you have listed on your signature are acid-loving species. It's actually better for their overall health and well being that your pH is between 6.2 and 7.
 
Ah, so you are saying that even a highly maintained tank will eventually tend to go more acidic? I've heard things about a tank "maturing" after 5 or 6 months. I'm just now going into the sixth month. Perhaps that is the reason. I don't mind the 6.6 PH although I'm concerned that when I switch the 55 with the Angels to a planted tank with Co2 that I will have a problem getting the correct amount of Co2 without making the PH drop too low (this switch is still a couple months away, though).

I guess I'll test it every day for the next week or so and see how it turns out. I'll post an update here again. Thanks for the help!
 
It's the wood that you have in the tank. Bog wood,peat moss and adding co2 to the tank will all drop the ph.

Bogwood contains lots of Humic acid, this will end up in the water and cause the pH to fall. :dance2:
 
depends on how much wood is in the tank along with other factors.
i had a similair problem with my 180g it dropped from 7.2 to around 6.0 within a week but it was my hardness there was no buffering.
i added 1 kilo of crushed sea shell to my externals and it was ok but then i also upped my filtration by a big amount and was able to remove half the sea shell as it was more stable.
your hardness seems ok though so im stumped
 
Even with a relatively strong buffer, the pH will still drop due to the nitrifying bacterial action and the bogwood. 6.6 really isn't that low anyway, so unless you do a 90% water change and then see the pH go from 7.6 to 6.6 overnight, I would seriously doubt the hardness is a problem.

Now as far as the CO2 goes...as long as you have a strong buffer I wouldn't suspect too drastic of a drop from it. My blackwater tanks are usually around 6.4-7 depending on how long since a water change, and both have DIY CO2. The pH hardly moves from it. Only the water changes have affected the pH.

But that doesn't mean it would be the case in your water, so I'm not guaranteeing anything.
 
My tank has been up a running for fours years and the ph has not dropped but once, when I didn't change the water for a while. As the water perams. are good then it has to be the wood in it. Wood will drop the ph faster, over time, then moss. or c02. If you want to prove that it is the wood then just take out the wood,do a water change and see.
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom