Problems with pH

[Larry Little]

Hey Everybody --

I need some help. The water supply in Tulsa has a pH > 7.6 My aquariums are showing pH that is off the chart. One tank is thriving with Crypts and Java ferns. I can't get plants to survive in the other tank. I'd like to bring the pH of the ailing tank down to the 6.8-7.0 range, but I can't seem to find a way to keep it there. I'm way "old-school" using white distilled vinegar to reduce the pH. I can get it down, but it doesn't stay down. Can anybody help? Thanks

 

[goatnad]

You could try adding driftwood or a substrate that will reduce the pH.

 

[Larry Little]

I forgot to mention that I have 2 good-sized pieces of driftwood, gravel substrate, and hard limestone rocks in the tank.

 

[Fresh2o]

You could mix some distilled or reverse osmosis (RO) water with the tap water to bring the pH to the desired level. You would need to be consistent with this moving forward. In your tank, in addition to the suggestions above, be cognizant of anything in the tank that can increase the pH (crushed coral, seashells, calcarious rocks).
When I was keeping a high tech planted tank, in the mornings the pH would be 7.8-8.0 but in the evening it would drop to 6.6-6.8 due to the CO2 I was injecting (CO2 temporarily lowers pH). The CO2 was for enhanced plant growth.

 

[goatnad]

I forgot to mention that I have 2 good-sized pieces of driftwood, gravel substrate, and hard limestone rocks in the tank.

It could be the limestone raising the pH. I would recommend testing your tap water then putting a piece of the limestone in a bucket of water and testing that water after a few days.

 

[King Fisher]

I agree with goat, the limestone is probably raising your pH.

 

[Fresh2o]

When I posted I did not see the part about the limestone. I would remove them and do another water change.

 

[King Fisher]

To add to fresh2o's last post.......I'd do at least four 50% water changes over a couple days after removing the limestone to get as much of the old water out as possible.

 

[Larry Little]

Hi everyone -- Thanks for the input. This is the type of rock I've had in aquariums since I was a small child. Unfortunately, the tap water is also reading the maximum of my test kit, about the same as the water in the tanks, above 7.6; just guessing, but I'd estimate that the pH is > 8.0.

 

[ZxC]

Nothing wrong with high pH. Java fern and crypts have always done well in my water (8.2 pH). No issues.

The ONLY way to get it down reliably is to use RO / Distilled water. The limestone is certainly not helping matters.

Make sure to take pH reading 24 hours after collecting a sample of tap water, this allows CO2 and other gases to off-gas from the water, giving you a correct value.

Might be worth investing into a cheap calibrated pH pen from amazon. They are more effective that liquid test kits. (if you are going to be testing and making changed).

 

[Larry Little]

Thanks, ZxC -- I'll check out the pH pen and do a pH test on 24 hr water. You're correct about Java Ferns and Crypts. I have them in my 40 gal. tank.

 

[Larry Little]

When I say "hard limestone", I mean flint; some of my rocks were sold as aquarium decorations "back in the day". My mom had some of them from before I was born.

 

[Larry Little]

Hi guys -- First, let me say thanks to everyone who has given me advice. I'm going to incorporate several of the recommendations.

I've done a 24hr. pH test on our tap water as recommended by ZxC and found it to be in excess of 7.6. If anything, it appears to be a bit higher than the aquarium water. I don't understand the chemistry behind this (it's been a long time since I took college chemistry), but I can't say that the flint-hard limestone is contributing to alkalinity.

I've ordered a pH pen to get more accurate readings. I plan to begin doing water changes using distilled water today.

My ultimate goal is to be able to have a pH that will support most live plants. I know that Crypts and Java ferns do well in the water I have, as they're both thriving in my 40 gal. tank with the same water source, but I want to expand my options.

Again, thanks to everyone who responded. If y'all think of anything else, please let me know.

Larry

 

[ZxC]

Hi guys -- First, let me say thanks to everyone who has given me advice. I'm going to incorporate several of the recommendations.

I've done a 24hr. pH test on our tap water as recommended by ZxC and found it to be in excess of 7.6. If anything, it appears to be a bit higher than the aquarium water. I don't understand the chemistry behind this (it's been a long time since I took college chemistry), but I can't say that the flint-hard limestone is contributing to alkalinity.

I've ordered a pH pen to get more accurate readings. I plan to begin doing water changes using distilled water today.

My ultimate goal is to be able to have a pH that will support most live plants. I know that Crypts and Java ferns do well in the water I have, as they're both thriving in my 40 gal. tank with the same water source, but I want to expand my options.

Again, thanks to everyone who responded. If y'all think of anything else, please let me know.

Larry

Larry,

a pH of 7.6 is perfectly fine for planted tanks, no real need to disrupt that. Here is an example of my tank running a degassed pH of 7.6:

And here is my tank running a pH of 8.2:

Loads of options at any pH!

If you want softer water, then yes using distilled or RO water is the best way. Just make sure not to use 100% distilled water because it will lead to an unstable pH and no minerals that fish / shrimp / snails and plants will need.

You can mix distilled with your tap water, or you can use 100% distilled but you must remineralize the water.

You will need to add:

Ca - For gH
Mg - For gH
CO3 - For kH

The cheapest way is to use:

CaSO4 - Gypsum - Plaster of Paris - Target 35ppm Ca
MgSO4 - Epsom Salts - Target 10 - 15 ppm Mg
CO3 - Potassium Bicarbonate - Potassium Carbonate - Target 1-2 degrees kH

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