What is best and fastest way to reduce PH?

[chongj88]

It seems that water from my flat has changed its PH from 7 to about 8.1 over the last few months. Consequently, PH in my tank has increased. Trouble is, I didn't know until the last 2 weeks. I have been consistently keeping the KH at 4 to 5 and topping up salt as I change water.

My questions as follows:

1. Does salt increase water's PH? I add salt primarily to help treat tap water and as some anti-disease precaution.

2. Apart from increasing CO2 into the water column, is there anything else I can do? Is it advisable to put in additives to lower PH?

Thanks for your help.

John

[bclee]

Don't bother too much the pH of the tap water.

Just maintain the KH of the water in your tank. The pH of your tank water will stay the same.

Additives to lower pH other than CO2 will lower your KH. Those additives are mostly acids.

BC

[chongj88]

Sorry if I wasn't clear enough... I actually plan to stabilize my ph around 6.8. I would rather not have it around 7 to 8 region. That is why I'd like to know if I should be patient and let CO2 does it job or introduce some ph lowering agent.

[vinz]

IME, even if my tap water is at 8pH, it eventually drops over the next few days. The lower pH in your tank water should also average it out initially.

Try this, get a pail of tap water. Test the pH, leave it overnight and test again 24hrs later. See what you get. Do post your results here, I'll like to see what you get too. If you can, test the KH and GH as well.

[chongj88]

Thanks for the suggestion Vinz. I will give that a try. I just need to go out and get myself and GH tester.

[bclee]

GH does not affect pH BTW.

pH is dependent on KH and CO2 level.

To lower pH, you have 2 options:

1. Add CO2
2. Add pH down additive, this will lower both you KH and pH.

Hope that this is clear.

If you have certain KH value and CO2 level, you will always get the same end pH. (Discounting the possibility of other buffering agents.)

That's why I suggest that you maintain the same KH level and not adjusting the CO2 level. This way you will always end up with the same pH.

The pH of you tap is high can be due to lower CO2 content or higher KH value.

BC

[vinz]

Err... I knew that... now why did I say to measure GH. Thanks BC.

[Allen_1971]

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On 1/7/2003 2:43:38 PM

It seems that water from my flat has changed its PH from 7 to about 8.1 over the last few months. Consequently, PH in my tank has increased. Trouble is, I didn't know until the last 2 weeks. I have been consistently keeping the KH at 4 to 5 and topping up salt as I change water.

My questions as follows:

1. Does salt increase water's PH? I add salt primarily to help treat tap water and as some anti-disease precaution.

2. Apart from increasing CO2 into the water column, is there anything else I can do? Is it advisable to put in additives to lower PH?

Thanks for your help.

John
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1. Salt should not impact your tank PH.

2. The best way is to use CO2. Some PH-down additives contain phosphates which are bad for planted tanks.

As for your tap water, as vinz mentioned, just leave it overnight and measure... water treatment sometime has procedures which cause the gases in the water to be outgassed... as such, you could have water with KH0 and PH of 8.2 like me....

[bclee]

ehh... salts like SO4--, PO4--- & CO3-- have some buffering capacity. They read as KH when you do a KH test. May indirectly affect pH.

BC

[chongj88]

Thanks guys. You have been most helpful. Unfortunately for me, this whole issue has been a comedy of errors and wrong assumptions which culminated in an almost total disaster last night.

I had always assumed that my pH pen was working well. So I assumed the values I got was accurate. Mistake #1 - I did not seek to verify with alternative sources. The pH pen told me my tap water pH was 8.0 while my good ol' Tetra test kit told me it was 7.0. Mistake #2 - I decided to increase the CO2 dosage from 1bps to about 2bps yesterday morning. The KH was maintained at 5. When I got home last night, 4 (out of 5) cardinals I had was dead, one I managed to save. 5 otos were almost gone which I managed to save as well. The biggest casualty were my shrimps... Of about 50 malayan and the recent addition of 5 yamatos, I only managed to save 2 yamatos... The rest went to shrimp heaven. []

I thus became a murderer... This made me very suspicious of my pH though my instinct told me it must be caused by CO2 poisoning. The pen reported pH of 7.8. Not convinced this time, I tested with the solution and result was a shocking 5.0! Suffice to say, I proceeded with more tests and conclusion is that my pen is a lemon. It is sitting next to me now waiting to be sent back to the manufacturer for testing (Eutech). Fortunately it is still under warranty but I am rather frustrated that the pen could give me such errorneous readings. Does anyone have similar experiences with pens from the same make/different make? Maybe I should just stick with the solution version instead.

Anyway, thanks for letting me vent my frustrations (more at my own impatience).

[loupgarou]

did you calibrate your ph pen before use?

[chongj88]

I guess in my haste to try it out, I didn't calibrate it.

[PeterGwee]

How long did you dip the pen in the tank water? Or did you remove some tank water just to test? My Eco test pen has been working fine since day 1..(did not calibrate even at that time..hahaaha...but later got the dennerle pH 7.0 solution to calibrate every 2-3 months after I used up the 1 time calibrating solution that came with the pen)..hard ti wonder why yours did not work? So sorry about the death of your fishes and shrimps...must be more careful next time.

And yes..always try to reset your or test new bubble rate when you are not working and willing to stay home for the whole day..or at most just a couple of hours outside so that you can monitor your fishes, shrimps and plants response. That's what I always do...[]

[chongj88]

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On 1/8/2003 10:46:58 AM

How long did you dip the pen in the tank water? Or did you remove some tank water just to test? My Eco test pen has been working fine since day 1..(did not calibrate even at that time..hahaaha...but later got the dennerle pH 7.0 solution to calibrate every 2-3 months after I used up the 1 time calibrating solution that came with the pen)..hard ti wonder why yours did not work? So sorry about the death of your fishes and shrimps...must be more careful next time.
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Thanks for your kind words Peter. If there is anything I learnt from this experience is patience.

On the topic of pH pens, are there any do's and don'ts associated with them? Is there a difference between reading straight from the tank vs. taking a sample of the water? I initially dipped the pen into the tank itself. Strange thing I noticed is that at nights when lights are off and no CO2 injection, the readings from the pen are stable, ie, no wild fluctuations. When I test during the day with lights and CO2 on, I get wild fluctuations. The readings wouldn't stay within a small region, it can range from 6 to 12 then degenrate into not readable status. However, if I take a sample of the water, the readings are stable. Can't help but to feel that there is something wrong with the pen.

Anyway, I will be sending the pen in for a check with the manufacturer later today. Will keep us posted.

[vinz]

Since there is still warranty, I assume it was bought recently... then it should be calibrated already. Guess we should take these things for granted. So lesson is, get some pH 7.0 solution and calibrate your pH pens before using. Or at least verify against another pen or a test kit.

Next, adjusting CO2... 1 bps to 2 bps is DOUBLE the rate of CO2 injection. CO2 poisoning aside, I would be concerned with the pH swing, buffered by KH or not.

Check out the tip on CO2 Adjustment.

[Alfa Low]

You can try using Nisso volcanic soil (Available in Farmart for S$45 per 8kg) or ADA aquasoil to achieve long term and staple low pH.

[kubrich]

i juz changed my gravel in my apisto tanks to nisso volca soil last week but the pH doesn't seem to have dropped...still remains at 7.0. quite dissapointed with the product...

[PeterGwee]

Guys...the problem here is CO2 related pH drop problem and probably pH test pen problem.

Using Aquasoil to drop pH will not increase CO2 level...no point here...and also the pH will sort of equalize to higher pH after several water changes (ADA aquasoil --- Amano himself say that the pH will go up after several water changes as the initial pH is very low due to accumulation of natural minerals and impurities..initial pH is 5.5 - 5.8 only!! Can be a rude shock to fishes and shrimps!!!)

Chongj88...it seems to me from your description that your pH test pen probe sure has some problem...taking pH reading directly from a planted tank is recommended as if you remove water from the tank, the CO2 will escape slowly which might give you a higher reading. If you are taking reading directly from the tank, the pH will drop gradually but should stablize at a point...the fact that your pH test pen show a reading of 12! shows that something is seriously wrong..it should have been like 7.0 and slowly decreasing to 6.8...then to 6.7.

[Alfa Low]

Is it due to you are using air-driven filter? But please do not worry as the pH will drop gradually. You will find the advantage of the product later.

[David]

hi chongj88

when i read your thread...i'm a little worried[]

which every coz of action you take, its best not to temper with PH down solutions....even if you have good brands around, let you tap water settle in your tank. Take readings over the next 2 days before taking any action.

constant PH swing of 1 point up or down (between afew hours to 24hrs) is going to stress you fish out...and risking them going into PH shock