Ph going down!

[Houliham]

How do I lower the ph in the water to 6.5 ?

[davidstcldfl]

VERY SLOWLY....if you have fish in the water....don't ask why I said that first.... :roll:

I use muatic acid (for swimming pools).
It takes very little....no more then a 1/4 cup of acid to a 1,000 gals. That little, will show a slight ph drop when tested. I wouldn't do it more then twice a day.....8 to 10 hours apart.

I use a BIG plastic drink cup, with a small hole in the bottom....add some water, then a little acid, top off the cup with more water. It 'slowly' drips into the water and is mixed in.

[krfoerster]

My PH comes out of the tap at 8.0 very high. I have sucess with the system but would like to get it down closer to 7. Other than a RO system would this acid work for me? Will it hurt my plant - fish. What is a good ratio for a 250 gallon tank of water.
Kenny

[stucco]

Try checking your ph 24 to 48 hours after drawing out of the tap and see if there is any difference. I don’t know why exactly, but mine goes down after a day or so.

[badflash]

A mature system will lower pH by itself. If the pH gets too low you are over feeding. If your make up water is too high, adjust it before adding. Aragonite sand is a good buffer in samll amounts to bring pH up.

[davidstcldfl]

I too, have heard what Stucco said, especially for well water.

[Brier]

Here is my experience for what it is worth. Lowering my ph took roughly 10 days. I have roughly 1800 gallons that out of the tap was 8.3. This is county water that comes from large wells deep in limestone. I slowly dripped a gallon jug of water with roughly one half cup of muriatic acid added. Re filled this daily for 10 days. Took nearly a half gallon of muriatic acid to bring it down to a ph of 6.8. There was a bounce every day by morning after the jug emptied in the night. The first few days the bounce was significant, for instance the first night the ph was down to 7.8, but by morning was back at 8.2. As the days went on the bounce became less, and less. To be on the safe side towards the 7th day, I started using less acid because I was using up some of the waters buffering capacity, and smaller amounts of acid were making larger adjustments.

There is no hard and fast rule to how much acid to add, as the buffering capacity or alkalinity will vary with the water source. Slow is safe. When funds allow, I will start using a Kold Sterile filter for make up water. Though these units should not affect the ph much, they should remove the buffers, and make adjustments easier, less acid needed to lower the ph. I would not use 100% RO water though, as it can remove all of the alkalinity, and without the buffering capacity, wild ph swings are possible. Though it seems different people have varying results with RO water.

[badflash]

tilapia need hard water. Ask Stucco about what rain water did to his fish.

[rfeiller]

carbon dioxide lowers ph oxygen raises ph. as water from RO, DI or distillation as the water balances with the surrounding air the ph will climb. water out of a good RO will be around 6.2 it will stabilize at about 7.0.
if the ph is coming down it is due to gasses in the air such as sulfer, carbon dioxide etc.

remember that anything you add to water to change it's characteristics, stays in the water. it adds stress to the animals and plants.

that is why RO, DI and Distillation are used to remove the minerals.

[Brier]

carbon dioxide lowers ph oxygen raises ph. as water from RO, DI or distillation as the water balances with the surrounding air the ph will climb. water out of a good RO will be around 6.2 it will stabilize at about 7.0.
if the ph is coming down it is due to gasses in the air such as sulfer, carbon dioxide etc.

remember that anything you add to water to change it's characteristics, stays in the water. it adds stress to the animals and plants.

that is why RO, DI and Distillation are used to remove the minerals.

See, I keep getting different info about this. The hydro store says the filtered water will come out around 6. The fish store says virtually unchanged. This Quote is from a FAQ on a RO system.

" Water Chemistry: Does the reverse osmosis process affect water pH?

In chemistry, pH is a measure of the acidity or basicity of a solution. We humans drink a variety of different beverages with varying pH ranges, from highly acidic orange and apple juice (3.3 pH), to mildly acidic milk and coffee (6 pH). Liquids that have a 7.0 pH are considered neutral and anything above that starts to become alkaline. Prior to any chemical reactions in the body, almost all drinks are naturally acidic. Water is an exception and can be both slightly acidic to mildly alkaline and drinking water ideally falls between a range of 6.5 to 8 pH.

Reverse osmosis filtration may or may not reduce the pH level of water at a noticeable amount. The pH difference after the RO depends on the composition of your input water source as well as the amount of gases such as CO2 in your local water supply. Water pH is actually a very complicated subject involving water and open air chemistry.

We have done many laboratory tests on the effects of our RO systems on water pH composition. The Southern California water sources used in our tests were slightly alkaline with an average pre-treatment rating of 8.12 pH. After filtration through our RO systems, the resulting pH averaged 8.06. Our results confirmed the conclusions of others in the scientific community –the reverse osmosis treatment process has very minimal effect on water pH chemistry.

People that wish to increase the pH of their RO water can also easily add an optional calcite filter to increase the alkalinity of their drinking water. "

What to believe? I have to assume different water sources are affected differently? I will try my own soon, and report my results.

[stucco]

Yes, I killed about 40 adult fish by adding rain water. :oops:

[rfeiller]

if the ph is caused from particulates such as salts, calcium, magnesium etc the RO will remove a percentage of these compounds (membranes are designed for specific applications, they can be designed to remove from low percentages of compounds on to up to 99. 75% of a particular compound. they are used for seperation of whey, removing dyes, detergents and on and on) removing the buffers will create water with a neutral ph. If the ph is cause from chemicals that are too small to be removed, but will pass through the membranes, such as some gasses in solution and solvents, it will not be able to correct that problem.

they were originally designed for desalinization, there are membranes made from both organic and non-organic compounds. if you do go RO make sure you have a system that reprocesses the water more then once with a recirculating valve, you can have a system that can recover up to 75% of the water otherwise you will be wasting most of the water.