# Help! My tapwater pH is rising!



## javalee (May 8, 2006)

I realized why my pH was off the top of the chart in the newly planted betta hex---the pH of my tapwater is changing! It always came out the tap at around 8.6-8.8, but it always dropped to 8.0 or even 7.8 if I aged it with an airstone for at least 12 hours. 

Recently, I've lost two fish, each in separate tanks, after doing a water change so I started testing again and realized that the pH is no longer dropping after aging so I have been adding 8.8 or higher water to my tanks! No wonder all my fish are sick with everything from slight cases of ick to fin rot! The pH is not dropping much in the tanks either (it's only 8.5 in my "plastic tank) as one would expect. The addition of CaCl2 and MgSO4 still seems to drop the pH in my NPT by removing carbonate through precipitation I'm guessing. But that reaction doesn't occur until after the water and Ca and Mg are added to the natural tank. So I don't want to be adding 8.8 water to my 7.8 NPTs! or to my "plastic" tank which is full of soft-water fish.

Diana had mentioned neutralizing water in my last post about GH so now I'm ready to discuss it! I first tried pool stores, so I have some muriatic acid or HCl. The only thing that worries me is the amount of resulting NaCl that will be in the water. I used to work in a biology research lab, but there I always knew the molarity of the solutions I was working with. Abita Springs bottled water comes from the same aquifer as ours and it has 47 mg/L so I think I can assume ours is the same. Has anyone tried using HCl to neutralize alkalinity? 

I figured Daina's suggestion for using HCl really would be best since the only part of the fish's water that will be altered is the pH and the resulting NaCl unlike cutting with distilled water which would reduce the osmolarity of their water. The GH in my "plastic" tank is 1dGH (only 2dGH in the NPT) so I don't stand to lose a lot of hardness. What do y'all think? I gotta reduce the stress on these fish soon! And I need to replace evaporation in my NPT, but I'm scared to do so.

Thanks!


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## DataGuru (Mar 11, 2005)

Roark has the best info I've seen on using muratic acid to reduce pH. His site isn't coming up for me at the moment, but hopefully it'll be back in time to be helpful.

I'd try adding the CaCl2 and MgSO4 to the change water when it's drawn up and see if that helps drop pH some.


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## javalee (May 8, 2006)

Thanks for the help, Betty. I'm waiting for that site to come up! I did try adding the Ca and Mg to the bucket and letting it bubble for a while, but it didn't work. Must be some kind of magic that catalyzes that reaction only in a NPT!

The only info I can get about our town water is that the experienced guy that used to manage our water system quit! Nasty town politics going on and I can't anymore answers as to what changed with the water and whether or not it's gonna stay that way.

If anyone else has any ideas or experience, I'd be glad to hear it while I wait for that site to come up. I may fiddle with the HCl in the meantime to see how much to use.


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## hoppycalif (Apr 7, 2005)

I don't have a natural tank, but adding Calcium chloride and magnesium sulfate to water will increase the GH of the water, which, if anything would also increase the KH, thus increasing the pH. KH measures alkalinity, and both the chloride and sulfate would contribute to alkalinity wouldn't they? If I had this problem I would buy a few gallons of distilled or RO water at the grocery store and dilute the tap water with it. I wouldn't use an acid at all.


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## plantbrain (Jan 23, 2004)

hoppycalif said:


> I don't have a natural tank, but adding Calcium chloride and magnesium sulfate to water will increase the GH of the water, which, if anything would also increase the KH, thus increasing the pH. KH measures alkalinity, and both the chloride and sulfate would contribute to alkalinity wouldn't they? If I had this problem I would buy a few gallons of distilled or RO water at the grocery store and dilute the tap water with it. I wouldn't use an acid at all.


No, Cl and SO4 have no impact of GH, although they do tend to be the anions.

pH climbing is normal in non CO2 tanks, the pH really is totally dependent on the time of sday one test.

It should be high in the afternoon, low before the lights come in the AM.
Adding HCl will simply roast the KH and can kill your fish.

Stick with using RO water etc if you want to reduce the KH or add a little peat to the tank's filter.

Regards, 
Tom Barr


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## DataGuru (Mar 11, 2005)

It's not coming up for me either.

Tom: Here's a good thread on how calcium can lower pH.

I'll bet whomever's doing the water treatment now added more soda ash than usual.

So what's your GH and KH out of the tap?

Have you tried the HCl on your change water yet?
When you do, be sure to let it sit afterwards and test again. I've read that if water is well buffered pH tends to bounce back up.

Another option would be oak leaves or peat moss.


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## javalee (May 8, 2006)

I had to put off the HCl test because the bottle looked to be contaminated or something; I think it was old. I can get more tomorrrow, but we had rain finally! 

So I gathered some buckets of rainwater in a perfect scenario. We had one downpour to clean the roof. Thirty minutes later we had another downpour to fill my buckets. The pH was a perfect 7 so I happily mixed it with my tap until the pH was appropriate and finally replaced the evaporated water in my 10g and have enough saved for the 29g water change.

I DO trust Diana, though, and if she has successfully used HCl in her tanks then I know it's possible. 

Betty, you're right. I was just thinking about the hours spent in chem lab titrating and watching nothing happen, nothing happen, and then BAM! the pH drops out the bottom. So I definitely will test it in a bucket and add only small amounts of the treated water at a time since my tank water is totally different than the tap water.

I don't know that I can depend on rain around here anymore. It seems that thunderstorms are few and far between these days. Anyway, I'd worry that I wouldn't be getting enough iron and other micronutrients like I do from my tapwater.

Tom, the problem is not my tanks; it's the fact that the water is coming out of the tap at a higher pH and it is no longer dropping as it ages. And, actually, the pH is lower in my natural tank than it is in my "plastic" tank.

Oh, Betty, the GH out the tap is still 0, and the KH...I'll have to test that one. It's deep artesian water; that's why it's parameters are so weird---full of sodium bicarbonate.


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## dwalstad (Apr 14, 2006)

javalee said:


> I had to put off the HCl test because the bottle looked to be contaminated or something; I think it was old.
> 
> The problem is not my tanks; it's the fact that the water is coming out of the tap at a higher pH and it is no longer dropping as it ages. And, actually, the pH is lower in my natural tank than it is in my "plastic" tank.
> 
> ...


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## javalee (May 8, 2006)

Thanks Daina! I'll keep all these points in mind when I use the HCl. Hopefully, we'll get our "old type" tapwater back sometime! I got some pure-looking HCl today. I'll be measuring before, measuring after, and measuring again. I may need a new pH test kit when this is over! I don't ever expect things to stay static when adding chemicals to a NPT (learned this from the subsequent pH drop after adding the Ca and Mg) so we'll see how well the NPT holds the pH of the added HCl water. I don't relish doing this, but looks like I have to in this situation. Gosh, I'd like to have reservoir water or river water instead of this artesian stuff!


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## javalee (May 8, 2006)

After having tried the pH reduction plan and realizing that the pH was not STAYING down, I'm beginning to wonder if this is worth it. The pH goes down nicely but 24 to 36 hours later both in the bucket and in the aquariums it goes back up, as Diana noted in her tank.

Also, after reading about how Diana used HCl for a "one time" pH reduction, I'm wondering if this is a sustainable to way to adjust tapwater. I mean, after months of topping-off with water adjusted with HCl to a natural tank, I wonder if I won't get that NaCl (or at least Cl-) build-up. I had to remember that I am adding CaCl2 already!

I retested my tapwater after sitting with an airstone and it's topping out at 8.4-8.6 now. The pH in my natural tanks is around 7.8 before adding tap water (presumably because the Ca and Mg I add precipitates out with the carbonate). So, should I just use the tap water as is, but add it carefully and slowly when doing water changes and topping off? Or should I adjust with HCl only when changing water? I'm wondering what's sustainable for the long-term maintenance of these tanks. Oh, I guess I could cut with bottled water too. Oddly, I found some local bottled water from the same aquifer as our tap water and it was pH of 7.2! This is getting to be a real pain! Especially since it's summer and I'm losing a lot of water to evaporation.


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## DataGuru (Mar 11, 2005)

So what's your KH the next day after you add the hcl?
I suspect you're not adding enough hcl. 

I dunno about the chloride. The one thing that's good about it is you wouldn't have to worry about nitrIte poisoning. 

What about adding your calcium chloride and letting your tap water sit out? or what about using calcium carbonate?


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## javalee (May 8, 2006)

Hi Betty,

I haven't tested KH yet after adjusting pH. I'll do that the next time I add water. I have tried letting the water sit out with the CaCl2 and MgSO4, even added an airstone, and it doesn't affect the pH; that only happens in the tank.

I'm mainly worried about chloride build-up. However, if I only add HCl when doing water changes (which I do rarely now) maybe that wouldn't cause a build-up. Then I could add regular tap water very slowly for evaporation? 

My crypts are tired of this pH issue!


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## DataGuru (Mar 11, 2005)

This may be why the calcium chloride isn't lowering pH in the change water. Roddy says KH needs to be in the 100 to 500 ppm range for the precipitation reaction to happen.


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## dwalstad (Apr 14, 2006)

javalee said:


> I retested my tapwater after sitting with an airstone and it's topping out at 8.4-8.6 now. The pH in my natural tanks is around 7.8 before adding tap water (presumably because the Ca and Mg I add precipitates out with the carbonate). QUOTE]
> 
> Hi Javalee,
> 
> ...


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## javalee (May 8, 2006)

Thanks Betty and Diana for keeping up with me on this!

Betty, I'm doing a water change today so I'll let you know what the KH is after 24 hours. It's still around 12-15 degrees (like the tap) right after adding the HCl. That's interesting about the concentration needed for the Ca++ to precipitate; I'm really impressed with how well you know your NPT chemistry!

Diana, thanks for taking a stab! The reason I always ran an airstone before adding the tap water to the tank is that doing so actually _lowered the pH from 8.6 to 8.0. I know this is counterintuitive, but I tried letting the water sit out for 24hrs without an airstone and it would read 8.5 or 8.4. However, running an airstone for 12 to 24 hours consistantly lowered it to around 8.0. Who knows!? The problem I'm having is that now the airstone is no longer lowering the pH of the tapwater.

I've also been using an airstone lately just to mix things like the CaCl2 into solution. The bucket I just prepared has HCl and CaCl2 and MgSO4 and a pH adjusted to 7.8 like the tank. I'm gonna add it to the tank now without bubbling it and leave some to sit out so I can test again tomorrow along with testing the tank just to see if it's rising in the bucket and the tank still. There are so many variables!

I do have two questions about this delimma:

1.)Should I just quit adding the CaCl2 and MgSO4 to my NPT since I THINK this is what's causing the pH to drop from the tapwater reading of 8.6 to the tank reading of 7.8? Then, the fish and plants would at least be stable even when doing water changes straight from the tap. I just thought this was pushing their pH range a bit high. Also I'm not positive that the pH in the tank would stay up if I didn't add the salts.

2.)What would baking soda do in this situation? It's interesting that everyone in a 45 mile radius who has a swimming pool is also struggling right now with their water chemistry! Apparently a pH above 8.0 is bad for pool maintenance too so I've been talking to my friends who have pools and one told me that they were advised to add baking soda to bring down the pH. That didn't sound right too me, but then baking soda's buffering powers, etc have always been unclear to me. Should I try baking soda when I have a KH around 16d out the tap?

I guess I could just start mixing with the bottled water from the local aquifer too since it's pH is around 7.0-7.5? That would work too? But what a hassel.

Thanks y'all for sticking with this and trying to help! I really do appreciate it. This problem is making aquarium-keeping much more complicated and physically taxing for me so I hope I can settle on a simple solution soon._


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## dwalstad (Apr 14, 2006)

If your KH is 15 degrees, then there's absolutely no reason to add sodium bicarbonate.

I think eventually you'll figure out a way to use your tapwater. I would try the HCl neutralization and then add the water to your tank. It seems like that would be the simplest solution. 

As to Ca and Mg, you really don't need to add that much to help plants. You can add a little bit every week. 

Water chemistry is complicated, but interesting. You'll get it eventually.


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