Unstable PH

[awolf3303]

Hi! I need help, ASAP. So, my alkalinity in my fish tank is 0-40 ppm right now, and I need to get it up another 100 ppm (at least). It is so low that one day my fish tank’s ph is a 7, and the next day it is a 9. I need to stabilize my PH by getting a high alkalinity in my tank. The issue is, my water has a PH of 6.8, and my tap water has a PH of 9. If I add baking soda to increase the alkalinity, the PH will skyrocket, possibly causing fish deaths. I do have acid buffer handy. Can someone please help me find a way to increase my alkalinity without drastically increasing the PH as well? Thank you!

 

[Sgooosh]

Hi! I need help, ASAP. So, my alkalinity in my fish tank is 0-40 ppm right now, and I need to get it up another 100 ppm (at least). It is so low that one day my fish tank’s ph is a 7, and the next day it is a 9. I need to stabilize my PH by getting a high alkalinity in my tank. The issue is, my water has a PH of 6.8, and my tap water has a PH of 9. If I add baking soda to increase the alkalinity, the PH will skyrocket, possibly causing fish deaths. I do have acid buffer handy. Can someone please help me find a way to increase my alkalinity without drastically increasing the PH as well? Thank you!

maybe alklinity buffer??? maybe rocks? bones? cuttlebone? i dont know, but how big is your tank>

 

[AdoraBelle Dearheart]

Wondering why your tank chemistry is so different from your tap water? A pH of 9 from the tap is rough...

I'm not great with the chemistry, but @Essjay is! We're fortunate to have our very own chemist.

To help her out, could you tell us some more about your tank please? What substrate is in there, and are you sure that it's inert? Have you added any decor like shells, any calcium, any rockwork? Things like these can make changes to your tank chemistry, so knowing what you're working with might help.

Also please say what chemicals you've been using in the tank, which products etc. I'm sure essjay will be able to help you more, but you'll need to give it some time since she's in the UK and it's 2:30 am here right now

 

[Colin_T]

What fishes do you keep?

Get a glass of tap water and test it for pH, ammonia, nitrite and nitrate. Then keep the rest of the water on a shelf for 24 hours and test it again, and again a week later. See if there is a change over time.

Your tap water might be buffered at the water supply company and this is giving you an unusually high pH. If this is the case, the pH might come down after 24 hours of being exposed to the air.

With a low KH, you could add a substance like pH down (sodium biphosphate) and then use calcium carbonate to raise the KH. You would have to do this in a bucket a few days before using that water in the tank. You can also filter the bucket of tap water through peat to lower the pH and then add a KH buffer.

 

[Guyb93]

I know you can use natural things to lower ph like lemons there juice has a ph of 2-3 so mixing will drop your ph , not sure on the effects it would have to your beneficial bacteria though , nobody wants a ph of 9 but if you can keep it stable at 9 maybe that’s the best choice , I’m no expert on water chemistry but I’d look for a level I can be sustained rather than suited

 

[Essjay]

With a very low KH, water is prone to pH swings. But in a fish tank, the pH usually drops rather than rises as waste products etc are acidic. You don't actually need to increase alkalinity (KH); you can allow the pH to settle at whatever it wants to be and keep fish suited to your pH/hardness.


But first we need to work out why your pH is swinging.

This is the first thing to look at

Get a glass of tap water and test it for pH, ammonia, nitrite and nitrate. Then keep the rest of the water on a shelf for 24 hours and test it again, and again a week later. See if there is a change over time.

Then look at the contents of your tank.
What is the substrate and what decor do you have in the tank? Some things can affect the pH. If you can give us a list we can spot any possibilities then you can do tests to see whether they are the cause.