pH of 8.0 at night...

TexasRock

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May 31, 2006
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OK, I need some help here... what can I do to get my pH lower in my tank?

During the day I can get it 7.3 sometimes 7.2.

I am building a new reactor as soon as my mag 3 pump comes in... the mag 3 will be a dedicated pump that will drive my reactor. The output of the reactor will be going into the intake of my return pump from the sump.

My sump has no bio balls, drip plate, etc... I use a 100 micron filter sock to catch the big stuff and a dual sponge filter for the bio load.

Any ideas???

Thanks!

Keith
 

Tom Barr

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Re: pH of 8.0 at night...

What's the KH?

Reducing that will reduce the pH.

Regards,
Tom Barr
 

TexasRock

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Re: pH of 8.0 at night...

Tom,

I wrote my city water quality lab and had them email me the latest water test, here are the results.

Sample Date: May 15, 2006
CONSTITUENT
Unit of
Measure
TAP
Total Alkalinity CaCO3 mg/L 130
Total Hardness CaCO3 mg/L 472
Total Hardness in Grains CaCO3 Grains 28
pH Hydrogen Ion SU 7.48
Calcium Ca+2 mg/L 98.1
Magnesium Mg+2 mg/L 55.3
Sodium Na+1 mg/L 219.5
Sulfate SO4-2 mg/L 339
Chloride Cl- mg/L 330.8
Bicarbonate HCO3- mg/L 158.6
Ammonia Nitrogen NH3-N mg/L 0.798
Nitrate Nitrogen NO3--N mg/L 0.951
Aluminum Al+3 mg/L 0.1
Fluoride F- mg/L 0.46
Ortho-Phosphate PO4-3 mg/L 0.16
Iron Fe+2 mg/L 0.02
Total Dissolved Solids TDS mg/L 1204

By the looks of this, my tap water has a HIGH KH... what do you think? As you can see, the tap water has a normal pH of 7.48.

Keith
 

VaughnH

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Jan 24, 2005
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Re: pH of 8.0 at night...

What reason do you have for wanting a lower pH? Plants and fish will do ok with what you have, except for rare exceptions. Lowering KH isn't nearly as easy as raising it - you can mix RO water with tap water to do so, but if there is no good reason to do so, why bother?
 

TexasRock

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Re: pH of 8.0 at night...

VaughN,

I got the impression that an indication of your CO2 saturation in the tank would be lower pH.

My pH goes from 8.0 (degassed tank at night) to about 7.3-7.4 during the day. I see MINIMAL pearling on plants and I'd like to see more pearling because isn't that an indication that they are growing well or am I misunderstanding that?

Keith
 

Tom Barr

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Jan 23, 2005
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Re: pH of 8.0 at night...

There's a trend afoot to lower the pH using only CO2 gasd by 1.0 pH units to get ~ 25-30ppm.

So if the water is 8.0, then you need to knock the pH down to 7.0.

Your KH is 130ppm or about 7, moderately hard, not too bad.
You could cut it 50/50 and get a KH of about 3-3.5 etc.

Do not concern yourself so much pH.
Use it to determine the CO2 is all.

CO2 and KH are more important than a particular pH.


Regards,
Tom Barr
 

TexasRock

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Re: pH of 8.0 at night...

OK, just for fun I tested my pH probe in the 7.00 pH solution that you use to calibrate. It came out to 7.4... so I recalibrated my probe. Now I will see what my pH reads. That should bring it down from the 8.0 reading to 7.6... which would mean I'd end up around 6.8 or so during the day.

Keith