Why Does My Ph Keep Going Up?

[poconoboss]

My PH straight from the tap is dead on 7.0 neutral. After a day or so it raises to about 7.6-7.8.

I did a test by putting some water in a cup testing the PH, and let it sit on the counter for a day and sure enough, it went up to 7.6-7.8, so that rules out anything in the tank causing it to raise. If I used a PH down product, it is only temporary, then it raises back up again.

I want to keep it neutral for a community tank.

I've never heard of a PH going up like that with seemingly no cause. Does anybody have any info?

I guess I should mention that I do have a water purification sytem in my house since I have well water. One stage removes impurities while the second stage adjusts the PH to neutral.

Any help would be appreciated.

Thanks!

 

[Bignose]

Many water companies dissolve extra CO2 in the water. It helps prevent mineral deposition in the pipes. When you sat the water out overnight, the extra CO2 in the water was able to equalize with the atmosphere.

However, there is very little reason to change your pH. A pH in the 7.6 to 7.8 range is perfectly fine for a wide variety of fishes to lead long, happy, healthy lives. What specific reason are you trying to lower your pH for?

 

[twistedlink]

tap water is colder, cold water holds CO2 a lot, as temperatures raise, CO2 is released.

CO2 in water makes carbonic acid (a very VERY weak acid) this makes your water 7

As the co2 goes into the air, the pH rises from lowering carbonic acid.

P.S. this effect can be seen in "global warming" graphs, CO2 lags behind temperature, temperature goes up from sun cycles getting stronger lately, heats the oceans, oceans release loads of CO2, CO2 gets blamed, CO2 is the result, not the maker.

 

[poconoboss]

Many water companies dissolve extra CO2 in the water. It helps prevent mineral deposition in the pipes. When you sat the water out overnight, the extra CO2 in the water was able to equalize with the atmosphere.

However, there is very little reason to change your pH. A pH in the 7.6 to 7.8 range is perfectly fine for a wide variety of fishes to lead long, happy, healthy lives. What specific reason are you trying to lower your pH for?

I have well water, no company involved.

I was trying to keep it around 7 (which is neutral) to accomidate the widest variety of fish without any problems.

I wasn't sure if 7.8 was too high or not.

 

[waterdrop]

Wow, pretty interesting for -well water- in a cup to just go up from 7.0 to 7.8. I wonder if Bignose can ask you a series of questions and get to the bottom of it. If anyone here can its probably him!

Personally I think a pH of 7.8 would be a great starting point, wish I had it! Mine is a little lower and during fishless cycling my pH heads all too quickly toward 6.0 and then I have to do a water change. Are you experienced with cycling?

Many threads on the forum here recommend that unless your pH is extreme you should plan to work with the pH your tap gives you and not use chemicals to change it. A pH of 7.8 is not extreme at all. I mean, eventually you may have opinions about it with respect to specific fish who have special needs but if you are a beginner hoping to develop a community tank then I would think 7.8 would be fine. Fish are pretty tolerant of pH, especially if changes in it are gradual.

 

[OldMan47]

If your well water settles at about 7.6 to 7.8 and stays there, I would leave it alone. As others have already said, water that is left out will lose any entrained gasses and the pH will tend to move. Things that move your pH down will usually only have a temporary effect on pH. The problem is you put the stuff in, the pH chnges, the buffering effect of the impurities in your water brings the pH back up and so on. For the fish its up, down, up , down, etc. That is much harder on them than being a little off their perfect pH value.

 

[Bignose]

Wow, pretty interesting for -well water- in a cup to just go up from 7.0 to 7.8. I wonder if Bignose can ask you a series of questions and get to the bottom of it. If anyone here can its probably him!

With it being well water, the only other thing I can think of0 is that the water might be under a fair amount of pressure and that shifted the equilibrium.

However, I the big thing is that I agree with the other posters that a pH of 7.8 is fine for the overwhleming majority of fish. Unless the fish is particularly sensitive or was wild caught from a particularly acidic body of water, 7.8 is more than fine. Some fish may not feel an overwhelming need to spawn at that pH, but that doesn't mean that they are terribly unhealthy.

What fish are you specifically trying to keep?

 

[poconoboss]

Funny thing happened in the last week, the PH has dropped a little and leveled off at about 6.8-7.0

Go figure.

I had added a small dose of PH down, but it didn't seem to do anything, then several days later it dropped a bit, then a little more.

To answer your question as to the fish I am keeping, I am keeping a peaceful community tank. Specifically: Various tetras (Cardinal, Rummy Nose, Black Neon, Hi Fin Serpae, etc.), German Ram, Dwarf Gourami, various cats and loaches, Guppies, Platies, Mollies, Pleco, Rainbows, Killifish.

Basically a wide variety.

 

[waterdrop]

You know, since this thread was still going, I decided to go back and read the first post by the OP and I for one had forgotten about that last sentence:

"I guess I should mention that I do have a water purification sytem in my house since I have well water. One stage removes impurities while the second stage adjusts the PH to neutral"

Looking at that again I wonder what the 2nd stage of that house purification systems does? Perhaps it adds something that is only quite temporary. That could be another explanation for the pH rising after sitting in a cup.

And, poconoboss, as for that last post I would just say in response to your comment about using "pH Down" that I've read over and over here on TFF that trying to use additives to directly get your tank to a specific pH and hold it there is a very frustrating and/or expensive experience in the long run. At least all the pH numbers your water seems to settle into one way or another seem to be within an ok general range according to the several people who have responded.

~~waterdrop~~

 

[poconoboss]

Looking at that again I wonder what the 2nd stage of that house purification systems does? Perhaps it adds something that is only quite temporary. That could be another explanation for the pH rising after sitting in a cup.~~waterdrop~~

That's what I was thinking.


What ever buffering agent is used may only have a temp. effect.

 

[monkey_biz]

as well as a fish keeper im a swimming pool plant engineer.
co2 is an acid used to reduce ph in pools to 7.4 as the disinfectant used (chlorine) is a alkali which raises the ph beyond the human comfort level of 7.8.
as well as ph the total amount of alkali in the water is very important (total alkalinity) you could have i nice ph of 7-7.2 but the TA is only 10-40 ppm.
bicarb will increase the TA without raising the ph to much, if the ph rises out of control beyond what you want then ph reducer can be used but this is normaly a
derivitive of bisulphate......... and so on........ added to thet the aerobic bacteria uses O2 in the water in the nitrogen cycle producing C6H12O6 + 6 O2 + 38 ADP + 38 phosphate → 6 CO2 + 6 H2O + 38 Adenosine 5'-triphosphate and anerobic used CO2 and produces all sorts of things C6H12O6 + 2 ADP + 2 phosphate → 2 lactic acid + 2 Adenosine 5'-triphosphate but that is getting deep...... lets just say it increases TDS
this is important as the TDS (total disolved solids) of the water as this is your breakpoint, to much and you will lose the ph buffering qualities of the water.

so in short find out what the water board adds to its water, find out your local tds and dont add to much chemical to your water as it all adds to the tds
to high a tds and all hell breaks out and you will chase your tail.

if they add co2 then this will dissapate naturally (temp dependant, colder water dissapates co2 slower) and you will get the true water value ph
if in doubt add something to increase the surface area of the water and thust increasing gas transfer ie airstone and air pump which incidentialy is what bathers do in swimming pools.
ph of 7.6 is fine. mine is 7.2 but i keep an eye on incomming tds and have very soft water in scotland anyway
if you need it more scientifically i can give you all the formulas to calculate it all yourself to give you your water balance

 

[monkey_biz]

im a numpty, must learn to read

also is your tank heavily planted??? if you take the readings first thing in the morning your ph will be lower as the plants will have spent the night not photosynthisising and thus releasing co2 and as that is an acid the ph will be lower as it is after say 5 hours of light where there will be less co2 as the plants will be using it

find out what the chemical is in your filter and its chemical properties, depending on your area in the states depends on the well water ph. some are over ph 8.
i think your TDS is high with all the addatives for safe drinking water.
if in doubt get a small RO unit for the tank to remove all the impurities. sounds like you have gone over the breakpoint and are using unbalanced water.
but hey if the fish are happy and you are getting no deaths dont fix what aint broken