Strange Ph Levels

[ryanred5]

I noticed a few days ago that the water in corner tank had quite a low pH, so today I did an experiment.

I got 4 clean glasses out and took a cupful from both tanks, plus one from the tap and one from the HMA filter, the results were as follows:

Tap - pH 7.25
HMA filter - pH 6.30
4ft tank - pH 7.30
Corner tank - pH 5.20

What the hell is going on with the pH in the Corner tank, why is it sooooooo low? The KH was 3 - 4 and GH was 9 of the Corner tank.

There is just sand and a weeny piece of bogwood for the BN catfish in that tank, no plants yet. All tests are fine, Ammonia and Nitritite are 0 and Nitrate is between 5 - 10.

Also I though HMA filters didn't lower the pH when water went through them, so what on earth is happening here?

Any help would be great?

 

[drobbyb]

I noticed a few days ago that the water in corner tank had quite a low pH, so today I did an experiment.

I got 4 clean glasses out and took a cupful from both tanks, plus one from the tap and one from the HMA filter, the results were as follows:

Tap - pH 7.25
HMA filter - pH 6.30
4ft tank - pH 7.30
Corner tank - pH 5.20

What the hell is going on with the pH in the Corner tank, why is it sooooooo low? The KH was 3 - 4 and GH was 9 of the Corner tank.

There is just sand and a weeny piece of bogwood for the BN catfish in that tank, no plants yet. All tests are fine, Ammonia and Nitritite are 0 and Nitrate is between 5 - 10.

Also I though HMA filters didn't lower the pH when water went through them, so what on earth is happening here?

Any help would be great?

Over time the conversion of nitrogen in ammonia, nitrite and nitrate all lower the ph. With tap water as close to neutral as yours, your KH (buffering capacity) isn't very much. If you aren't already you need to be doing weekly waterchanges. If you get the waste out before you KH drops below 4 (this is where ph drop occurs) you will have neutral water.

To fix this problem I recommend that you do a 25% water change every day for 4 days and a 50% water change every week.

 

[ryanred5]

Okay I stood a container of HMA water for a couple of days and the pH went back up to 7.

I've changed the water twice using the increased pH HMA water but the pH in the corner tank is still around 5.

I just don't understand it at all, why is it so low, is it worth adding a small amount of bicarbonate of soda to increase the pH, will it aso increase the KH too cos that's at 2?

If so do I add it at each water change, any idea of how much to add?

The fish are all doing okay btw, eating normally etc.

 

[drobbyb]

Okay I stood a container of HMA water for a couple of days and the pH went back up to 7.

I've changed the water twice using the increased pH HMA water but the pH in the corner tank is still around 5.

I just don't understand it at all, why is it so low, is it worth adding a small amount of bicarbonate of soda to increase the pH, will it aso increase the KH too cos that's at 2?

If so do I add it at each water change, any idea of how much to add?

The fish are all doing okay btw, eating normally etc.

Adding baking soda will raise your pH and KH. Start off with 1 teaspoon and wait 24 hours. Test again, if it is still too low repat until you get it high enough.

 

[tenohfive]

Is the pH actually doing your fish any harm? If they are happy enough I'd leave them be, as fluctuating pH levels are often more harmful than a high or low (but stable) pH.

 

[drobbyb]

Is the pH actually doing your fish any harm? If they are happy enough I'd leave them be, as fluctuating pH levels are often more harmful than a high or low (but stable) pH.

pH of less than 6.5 will severly hinder your biological filter.

 

[TylerFerretLord]

If you want to raise it get some coral gravel and add a bag of it to your filter. It will help buffer and raise the ph to about 8, but frequent water changes will keep it from going that high. You can also do this with shells in the display.

 

[ryanred5]

Thanks for your replies they are great.

I was thinking of doing a big water change tomorrow, how much of a WC would be a good idea, bearing in mind I've got Discus in the tank?

If I put bicarcb in the water, what do I add it to, is it the tank directly or to the water I'm putting in the tank at a WC?

Or as the last poster said, is it a better idea to go with coral sand/shell way?

Thanks.

 

[drobbyb]

Discus love clean water. I do 2 50% waterchanges a week for my rainbows to keep them breeding. 50% halves your nitrates. I actualyl have experience in raising pH as my water from the tap is pH 6.6 KH <1 GH <1 (extremely soft) It has no buffering capacity at all. I just plopped crushed coral into nylon tuxedo socks and put it in my filters. This keeps my pH stable and I bet it would for you too.

 

[ryanred5]

I had asked if coral sand was okay, but as I've used tuffa rock before weve bought a piece to put in the tank.

The KH of the tank water is 1 - 2 and GH is 7 - 9, so very soft too. The tap water is 5 for both.