The Planted Tank Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #1 ·
Well since going from my 10 gal to my 36 gal. tank my PH seems to be very different from each tank. My tap comes out at 6.8, the ten gal was at 6.8 my 36 gal started at 7.2, and has since moved up to 7.8. I am baffled by the change over the past month. The only difference between the two tanks is my substrate,one plastic decoration and filter. Everything else is from the 10 gal when I tore it down. What would cause this? The substrate is Active-Flora which states on its bag that it will not alter the PH of the water.
I do 25% water changes every week.

I am using a liquid master test kit to test the water
 

·
Registered
Joined
·
336 Posts
What's the KH of the water?

I suspect it may be "hard".

I used to have the same problem. The KH was over 450ppm (25 DKH) and PH would go from 7.1 to 8.2. Since then, water supply has changed and now it's 33ppm (1.8 DKH) and PH is now 7.2 and goes to 6.8 (I'm running CO2 and have raised the KH to 4.2 using baking soda.)
 

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #7 ·
I think you should check it and not assume.
I did a test on it prior to posting my initial post, it tested at 6.8 It does occasionally test a tad higher, although never as high as the water that is in the 36 gal.
 

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #8 ·
What's the KH of the water?

I suspect it may be "hard".

I used to have the same problem. The KH was over 450ppm (25 DKH) and PH would go from 7.1 to 8.2. Since then, water supply has changed and now it's 33ppm (1.8 DKH) and PH is now 7.2 and goes to 6.8 (I'm running CO2 and have raised the KH to 4.2 using baking soda.)
I will grab my fathers KH kit within the next couple days (lives only about 10 miles from me) and give it a whirl.
 

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #10 ·
Hmmmm....Colorado + January = 3 days to go 10 miles. :proud:
lol, it is actually quite dry right now. I work two jobs so getting much free time to sneak away from the family to get over there is a chore in itself.
 

·
Fresh Fish Freak
Joined
·
24,403 Posts
You might bump it up to 50% weekly and see if that helps maintain more stable parameters.

How long has the 36gal been up and running? If it's been more than a year, chances are good the TDS have accumulated/concentrated in the tank simply from evaporation.
 

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #12 ·
You might bump it up to 50% weekly and see if that helps maintain more stable parameters.

How long has the 36gal been up and running? If it's been more than a year, chances are good the TDS have accumulated/concentrated in the tank simply from evaporation.
I will give it a go with the 50% changes and see if that helps. The tank has been up for a little over a month so far. Everything else has been very stable. I added my 10 gal's filter and every plant was moved over to help seed the tank quickly.
 

·
Registered
Joined
·
21,012 Posts
A rising pH almost always means a rising KH, and that comes from dissolving carbonates, usually rocks or the substrate. Assuming you don't inject CO2, the constant amount of CO2 in the water, with a rising KH has to result in a rising pH. Regular water changes will limit the amount of increase.
 

·
Fresh Fish Freak
Joined
·
24,403 Posts
I agree, if your tank's pH is fluctuating that much in the space of a month, it's likely that your kH is rising also. And kH shifts can be really problematic for fish, so you probably should track down the source.

(ActiveFlora is really new on the market, and that's my best guess based on the info so far...)
 

·
Registered
Joined
·
4,391 Posts
Discussion Starter · #15 ·
I agree, if your tank's pH is fluctuating that much in the space of a month, it's likely that your kH is rising also. And kH shifts can be really problematic for fish, so you probably should track down the source.

(ActiveFlora is really new on the market, and that's my best guess based on the info so far...)
That is the only thing I suspect as well, although the bag says it will not change it. Everything is out of the 10 gal. Except the canister filter, substrate and a plastic decoration. My canister filter has only carbon, and the bio media for bacteria. Looks like I will begin 50% changes to help control it. First one will start tonight. Thanks guys for the help. I will let you know how things turn out.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top