Baking Soda and PH?

[studmaster]

Hello everyone!

I've read a few places now that you can use baking soda to raise your PH level. Anybody have any luck? I grabbed some out of my fridge and did some tests, but I couldn't raise it at all. I'm using AP liquid high range test kit.

I'm just wanting to raise the PH of the water in the solution I'm using to hatch brine shrimp to feed to my molly fry. PH up seems to work, but I was hoping to use baking soda.

Thanks in advance.

 

[Musket]

sorry never heard of this. Glad you are testing in a non fish environment first. Also, if this is a true method, you may be having problems due to the age of the baking soda?? How long has it been in the fridge? Has it picked up odors??? This could be a factor...
Let us know how your tests go. This could be interesting.

 

[jsoong]

Baking soda will alter pH, but how much depends on what your pH is to start.

Equilibrium pH of NaHCO3 is 8.2. That is the pH of water saturated with HCO3. If your pH is already close to that .... adding HCO3 won't do too much.

Roughly, 1 tsp of baking soda in 50 gal of water will increase the KH by 1. To find the pH:

[H+]start x [HCO3-]start = [H+]end x [HCO3-]end
...Henderson-Hasselbach equation with CO2 level constant

pH = -log [H+]
KH = [HCO3-] assuming you have no other buffer other than CO3/HCO3

If you have other buffers in the water (phosphates, any other pH altering chemicals), this equation will not be valid. Having a second buffer will also negate the baking soda effect. The second buffer will hold the pH at its equilibrium value & prevent the pH from moving when you add baking soda <until you added enough to overwhelm the buffer, then you'll have a sudden pH shift.>

 

[studmaster]

Hello again,

My PH to start is 7.4. A good point is that yes it has been in my fridge for a LONG time, so that might effect it greatly. I'll have to pick some new baking soda up at the store.

I started with roughly a litre(quart) from the tap. Added two tablespoons of salt. Then tested PH, then added some baking soda, then tested, then continued this until I finally gave up after about 5-6 tablespoons of baking soda. If the baking soda had went bad from being in the fridge a long time, it probably threw off the tests.

As these baby brine shrimp will be fish food in about a day, I just need the PH to stay above 8 for 24-48 hours. And it would be nice to do this cheaply.

 

[DeFeKt]

got any limestone in your garden?

 

[Apocalypse_Gold]

Epsom salts will also buffer up your pH.

 

[studmaster]

no, I live in an apartment, where can you get limestone? I tried the LFS's but they didn't carry any. I do have epsom salts....I might give those a try. What PH does limestone bring the water up to?

 

[tropicfishman]

you may wanna avoid chemical addivites to raise your PH or lower it, I used it forever and never realized that drastic swings from 6.6 to 7.0 will severly stress out your fish if not kill them, most fish can onlyt tolerate a PH increase or decrease of .2 increaments at a time, an example would be 6.6 to 6.8 or 6.6 to 6.4, even then it should only be raised that much every 24- 48 hours to prevent fish stress or loss, I would stick with the " natural " way, such as limestone, salts, etc.

 

[studmaster]

I'm just using it to hatch baby brine shrimp in a seperate container, so that will never affect my fish at all. A small container at that, so limestone probably wouldn't work for me. I'll try fresh Baking Soda, or Epson Salt....then if those fail, PH Up. I am however looking for limestone for one of my 10gal that have a few mollies in it. My PH is a little low and it would be nice to get it up a couple notches.

 

[Lonewolfblue]

Crushed coral also raises ph over time. Wouldn't raise it instantly, but if you plan on doing the brine shrimp over a length of time, it might work. Would just need something to bring up the ph in the beginning. The CC should keep it up.

 

[Fishyfanatic]

I highly recommend crushed coral if you are trying to inrease your pH. Not only will it increase the pH, but it will also increase the hardness. It is a slow method and is natural. It is a "set it and forget it" type of method. You do not have to dose at every water change like you do with baking soda or chemicals. About every 6 months or so just replace the bag of cc.

 

[studmaster]

Crushed Coral sounds great for my 10 gallon, and maybe I'll get some for that, but for hatching the brine shrimp most people discard the water after one batch. My batches will be about a litre each time. So it would be best to have something that made the water instantly a higher PH.

I just tried epson salt at the ratio of about 1 part epson salt, 10 parts water and it didn't change my PH. I was kinda surprised as I thought that much epson salt would put the PH off the charts.

I'm trying to understand the whole "buffer" issue. What are some of the commom buffers? I might have a lot and therefore it's keeping me at the same PH level.

 

[Lonewolfblue]

What about a couple of fresh gallon buckets. Have some at the ready with CC in them, then when you do a hatch, discard the water and refill the empty bucket. That way it's ready when you need it. For the length of time between hatchings, might just have 3 buckets or jugs, that way each jug gets to set several days. Just another idea to through out there.

 

[studmaster]

Keeping a couple gallons of water with CC in it sounds like it could work. What PH does CC keep the water at? It is expensive at LFS's?

 

[Lonewolfblue]

Not sure on the ph, but CC at bigalsonline is a little spendy. I ordered some tonight, and it's considered heavy shipping. See if the lfs can get it for you, might be cheaper that way.

 

[jsoong]

A cheap source of limestone would be a landscape place ..... although you usually can't find crushed so you'll need to let your water sit for quite a while for the limestone to dissolve in. The equlibrium pH for limestone or cc is the same as HCO3 about 8.2.

For your brineshrimp, I think the best thing is to use baking soda. You'll need to increase your KH by 10 or 12 to get from 7.4 to 8 ... that's about a tablespoon in 10 gal. I'd try some fresh baking soda.

The commonsest 2nd buffer in tap water is phosphate from agricultural runoff. For the small amount of water you'll need, you can just bypass all of the second buffer issues & get a gal jug of distill water & dump in some baking soda to get to the pH you want.

one other possibility, some water have dissolved CO2 (mostly well water) that will keep your pH down. In that case, you need to wait 24 hr & re-measure your pH, the CO2 would out-gas & you'll get a higher final pH.

 

[Fishyfanatic]

CC will raise your pH up to 7.8.

 

[Jaybird]

I've used baking soda to help my water, but not to bring up the PH. My tapwater comes out an even 7, but is so soft that it has 0 buffering. I put in a little baking soda when doing a pwc just to help buffer the water so that the PH keeps stable.

 

[studmaster]

Crushed Coral sounds great for my 10 gallon, and maybe I'll get some for that, but for hatching the brine shrimp most people discard the water after one batch. My batches will be about a litre each time. So it would be best to have something that made the water instantly a higher PH.

I just tried epson salt at the ratio of about 1 part epson salt, 10 parts water and it didn't change my PH. I was kinda surprised as I thought that much epson salt would put the PH off the charts.

I'm trying to understand the whole "buffer" issue. What are some of the commom buffers? I might have a lot and therefore it's keeping me at the same PH level.

edit:
Just tried some Epsom salt I had around the house. Took a litre of tap water, added 1 teaspoon ES, took PH reading, no change. Added 1 Tbsp of epsom salt, tooking PH reading and no change. Nothing I do accept using PH Up will increase my PH.....but I don't like to use that because I've heard nothing but bad things about it.

So I decided to use some bottled water....and......same thing. They both read about 7.4 with epsom salt. Am I misunderstanding what Epsom salts do for water? Do they not raise PH? (directly or indirectly).

 

[jsoong]

I am a bit confused with your bottled water experiment .... did it read 7.4 before or after adding MgSO4?

I have not heard of using MgSO4 in aquarium circles to increase the pH. I read in the KRIB that MgSO4 will increase GH (obviously), but will not chnage pH.

However, SO4 is a buffer, and when adding any buffer, it will drive the pH towards its equilibrium value. This is true of most buffers, they don't increase or decrease pH per se, they just drive the pH towards a specific value. So the pH can increase or decrease depending on where you start from.

I don't know the equilibrium pH of MgSO4 off hand, so I experimented. I made a saturated solution of MgSO4. My pH test reads this as 7.5. If 7.5 is the equilibrium pH, then it is no surprise that you cannot get pH past 7.5! <So MgSO4 is only useful in increasing pH of acidic water, and only by modest amount.>

BTW I did a control with a saturated solution of baking soda ... The pH is 8.5 (ish). This tells me that my pH kit is working <and what I read about equilibrium pH of HCO3/CO3 is true.>