What is a safe rate to raise pH (with baking soda)?

[Mmathis]

IOW, I know that you want the increase to be gradual, but how much should you shoot for over any certain period of time? Like, how many "points" in a 24 hour period?

=======================

I just noticed that the 2 small goldfish in my 20 gal tank were suddenly acting very hyper, so I checked the water.....

• Ammonia 0ppm
• Nitrites 0ppm
• Nitrates slightly positive but don't recall the #
• pH almost not detected, and the card for "low" only starts at 6
• KH way low -- water changed color with first drop of reagent
• Source water (tap) 8.8 - the most lovely shade of purple

=====================

The tank has just cycled. I was reading that during "cycling," the bacteria can cause problems with the pH, and it was recommended that you increase air flow/increase surface agitation -- I've done that. Tomorrow, but not now, at midnight-thirty, I'll add some crushed oyster shell and do a water change if necessary...... Our water has a low KH, so it's something I fight with to keep at a good level.

I also read that a rule-of-thumb ratio of baking soda is 1 tsp / 5 gallons. I was afraid of going too fast, so only added 2 tsp. instead of 4 (20 gal tank). That raised the pH to around 7.2 and the fish look more comfortable, so I stopped there. And while 7.2 is a good pH, my tank & pond stay around 8.2 on average.

But I couldn't find a reference for how FAST to raise the pH.....

@crsublette @fishin4cars @Dave 54

 

[Dave 54]

IOW, I know that you want the increase to be gradual, but how much should you shoot for over any certain period of time? Like, how many "points" in a 24 hour period?

=======================

I just noticed that the 2 small goldfish in my 20 gal tank were suddenly acting very hyper, so I checked the water.....

• Ammonia 0ppm
• Nitrites 0ppm
• Nitrates slightly positive but don't recall the #
• pH almost not detected, and the card for "low" only starts at 6
• KH way low -- water changed color with first drop of reagent
• Source water (tap) 8.8 - the most lovely shade of purple

=====================

The tank has just cycled. I was reading that during "cycling," the bacteria can cause problems with the pH, and it was recommended that you increase air flow/increase surface agitation -- I've done that. Tomorrow, but not now, at midnight-thirty, I'll add some crushed oyster shell and do a water change if necessary...... Our water has a low KH, so it's something I fight with to keep at a good level.

I also read that a rule-of-thumb ratio of baking soda is 1 tsp / 5 gallons. I was afraid of going too fast, so only added 2 tsp. instead of 4 (20 gal tank). That raised the pH to around 7.2 and the fish look more comfortable, so I stopped there. And while 7.2 is a good pH, my tank & pond stay around 8.2 on average.

But I couldn't find a reference for how FAST to raise the pH.....

@crsublette @fishin4cars @Dave 54

Well its quite a while now since weve had to resort to opening our little pot of Bacing soda from the first aid kit as nowadays we use a calcified seaweed to bultster our Ph/Kh but thats on the pond and we dont use fish tanks anyomre .
But looking back however and if I remember righly we would use the very same formula, which works out at a tsp of baking soda to 5 gallons imperial/ not sure on the US measurements but it shouldnt differ in our view.
This formula of a tsp to %gallons imperial ? US, will have the effect of raising not only your pH but you Kh levels as well Maggie so your calculations are indeed correct there.
Personally I'd add a tsp allow time for it to take effect then test your water, then if the Ph/Kh is still low add add some more and re-test until you get to the required Ph/Kh.....but take it one tsp at a time until you rech the required level.
Yes bacteria can and will have the effect of lowering the Ph/Kh of your tank somewhat, normally to about 6-6.5 again if I remember correctly so dont quote me on this .
Bacteria do best at a pH of 7.8 but there is no need to target this as anything over 7.2 is fine, adding an airstone will also help.

Dave

 

[fishin4cars]

Maggie, I shoot for bring the PH up .2-.4 per 24 hour period, But that may not work in your case as you need to get it up quicker than that. Using baking soda your going to make the PH climb to 8.3, you don't have much choice if your going to use baking soda. I would mix 2-3 tablespoons in a gallon of water and mix well, then every couple of hours add about 1/2 cup slowly to the pond being treated. test each time until the PH of 7.0-8.0 is reached. Then continue adding once a day until you get the KH back up to 80-120 ppm. Slow is best but your in a critical state right now and very close to if not already experiencing PH crash.
Thinking a little more on this, may actually want to do a water change first, this will help raise the PH and KH some and relieve some stress off the pond before getting started, it also may help lower the nitrate which in most cases I have experienced, is usually high when KH and PH drop like that.

 

[Mmathis]

Thanks, Dave & Larkin! That gives me a baseline. I don't think I read a single article that told you how fast [or slow] to make pH changes.

I'm getting a late start this morning......yawn.....but will check the water again once I wake up.

Now, on to another question -- for my education & as a future reference: what would make a tank's pH drop so suddenly in just a few days??????

 

[crsublette]

IOW, 1) I know that you want the increase to be gradual, but how much should you shoot for over any certain period of time? Like, how many "points" in a 24 hour period?

=======================

I just noticed that the 2 small goldfish in my 20 gal tank were suddenly acting very hyper, so I checked the water.....

• Ammonia 0ppm
• Nitrites 0ppm
• Nitrates slightly positive but don't recall the #
• 2) pH almost not detected, and the card for "low" only starts at 6
• KH way low -- water changed color with first drop of reagent
• 3) Source water (tap) 8.8 - the most lovely shade of purple

=====================

The tank has just cycled. I was reading that during "cycling," the bacteria can cause problems with the pH, and it was recommended that you increase air flow/increase surface agitation -- I've done that. Tomorrow, but not now, at midnight-thirty, I'll add some crushed oyster shell and do a water change if necessary...... Our water has a low KH, so it's something I fight with to keep at a good level.

I also read that a rule-of-thumb ratio of baking soda is 1 tsp / 5 gallons. I was afraid of going too fast, so only added 2 tsp. instead of 4 (20 gal tank). That raised the pH to around 7.2 and the fish look more comfortable, so I stopped there. And while 7.2 is a good pH, my tank & pond stay around 8.2 on average.

4) But I couldn't find a reference for how FAST to raise the pH.....

@crsublette @fishin4cars @Dave 54

1) I know that you want the increase to be gradual, but how much should you shoot for over any certain period of time? Like, how many "points" in a 24 hour period?

Generally, I only do 1 degree per 24 hours. So, this can be anywhere around 0.2~0.4 pH change, depending on how low of KH you are.

For those unaware, here is the Baking Soda - Alkalinity calculator.

Now, I know fish can tolerate much more of a pH change than folk give them credit for tolerating, but I still stick to recommending only 1 degree (1 dKH or 17 ppm alkalinity) change per 24 hours for all circumstances.

The reason for the wait is due to the fact that water actually equilibriates quite slow when it comes to changing alkalinity. There are many, many, many chemistry "dances" being involved here whenever water's alkalinity is changed. Change water's alkalinity is a quite major ordeal, that is in the chemistry world. The occurrence of "alkalinity jumping" is quite common if you do not wait a proper amount of time between each dosage. 24 hours should be enough wait for the water to reach its new equilibrium if you have good water flow, aeration, etc.


2) pH almost not detected, and the card for "low" only starts at 6

Quite likely much lower since the conventional low range pH testers only test down to 6.0.

If your fish have not been accustomed over a period of time to this low pH, then this is a problem. You are correct to be concerned.


3) Source water (tap) 8.8 - the most lovely shade of purple

What is your source water's alkalinity?

City water can commonly have 8.8 pH with a low alkalinity, that is due to the municipalities water treatment process. Much more important to know the alkalinity, that is as most folk know it as "KH".

If your source water has a higher alkalinity than your pond, then you can start doing a slow 40% water change, that is doing this before dosing the pond with baking soda. If the source water has a quite low alkalinity, then do not use it in this manner during this period of trying to stabilize your pH.

I would also look into adding more calcium carbonate, which is a slow release. Crushed oyster shell is the cheapest, but there is all type of formulations as talked about in post#6 of thread "Raising KH with Coral or Oyster".

So, if you were doing all this plus dosing a 1 degree alkalinity change every 24 hours, then this should be good enough and should raise your pH slowly and safely for your fish.


4) But I couldn't find a reference for how FAST to raise the pH.....

Yeah, for something this important, then it would seem like it'd be much easier to find more consistent advice on this matter. Unfortunately, I never could find out either, that is "how fast to safely raise the pH".

Personally, on these issues of pH, I side with the "better safe than sorry" crowd, which I do not like doing too much.

 

[fishin4cars]

Thanks, Dave & Larkin! That gives me a baseline. I don't think I read a single article that told you how fast [or slow] to make pH changes.

I'm getting a late start this morning......yawn.....but will check the water again once I wake up.

Now, on to another question -- for my education & as a future reference: what would make a tank's pH drop so suddenly in just a few days??????

Maggie, Charles can probably answer this better than most but I'm quite sure it will be a lengthy post and in detail as to why. Simple version is, THE KH or buffer ran out, the natural process of breakdown still takes place and the PH swings from the CO2 and Oxygen being processed in the pond. As you see once the KH drops the PH can swing big and fast, that's why one of the most important test that a pond owner can keep track of is the KH, of course ammonia, nitrite and nitrate are very important, but KH to me is the most important to maintain, it's cheap and easy to keep the KH up and with enough buffer and regular checks you shouldn't have this problem in the future.

 

[Mmathis]

Water was stable when I checked it this morning. KH was up to 80, pH was 7.4, nitrates still trace. Fish seem comfortable. I'll check water again tonight (well, later since it's already "tonight"). As long as my KH stays up, I don't think I'll add any more baking soda just yet. And BTW, this is my indoor tank, not the pond, though it doesn't matter as the effects & treatments would apply to both,

Our source water has a low KH, so I keep oyster shells in the pond. I normally keep some in the tank, as well, but didn't this time.

 

[crsublette]

Maggie, Charles can probably answer this better than most but I'm quite sure it will be a lengthy post and in detail as to why. Simple version is, THE KH or buffer ran out, the natural process of breakdown still takes place and the PH swings from the CO2 and Oxygen being processed in the pond. As you see once the KH drops the PH can swing big and fast, that's why one of the most important test that a pond owner can keep track of is the KH, of course ammonia, nitrite and nitrate are very important, but KH to me is the most important to maintain, it's cheap and easy to keep the KH up and with enough buffer and regular checks you shouldn't have this problem in the future.

Hey hey now. Larkin... I believe you are inferring something here... Just for that... I am going to simply " Like " your post.

 

[crsublette]

Water was stable when I checked it this morning. KH was up to 80, pH was 7.4, nitrates still trace. Fish seem comfortable. I'll check water again tonight (well, later since it's already "tonight"). As long as my KH stays up, I don't think I'll add any more baking soda just yet. And BTW, this is my indoor tank, not the pond, though it doesn't matter as the effects & treatments would apply to both,

Our source water has a low KH, so I keep oyster shells in the pond. I normally keep some in the tank, as well, but didn't this time.

Yep, pretty much. I had a good pompous template response for folk that think that aquariums and ponds are so uniquely different at every angle. Only difference is scale and location; other than this, nope, not so different.

Water's alkalinity in an aquarium reacts the same as the water's alkalinity in a pond.

Since this is an indoor tank, rather than oyster shells, you might want to look into using those specialized aragonite sands, as referenced within the hyperlink of post#5, that helps to stabilize the pH.

 

[Mmathis]

Yep, pretty much. I had a good pompous template response for folk that think that aquariums and ponds are so uniquely different at every angle. Only difference is scale and location; other than this, nope, not so different.

Water's alkalinity in an aquarium reacts the same as the water's alkalinity in a pond.

You mean, I got something right.......?


But sorry, I stole your pompous template response opportunity, Charles