Building up stuff in RO water to have pH 7

My tap water is bad and wildly inconsistent with big swings. So I need to use RO water.
My tank is done cycling (woo Hoo!) so I’m ready to do water changes, add plants and then fish.

I want to build up my RO water to a pH of 7 and a hardness of 10. Do I ONLY need Equilibrium and Neutral Regulator? Or do I ALSO need baking soda? I want to be sure I have the right cocktail and have tested it before I add plants. Thanks for any help!

 

What’s the ph without changing it? As long as it’s not unbelievably low you should be ok depending on your stocking

 

What’s the ph without changing it? As long as it’s not unbelievably low you should be ok depending on your stocking

My understanding is that RO water is around 6.5-7 until it is exposed to air and then it begins to drop to around 5-5.5. I might be wrong but that is what I read.

 

Any additional thoughts?

 

RO water tested for pH over 96 hours, exposed to the atmosphere never moved from 6.25. It doesn't have any buffering capability so a little KH is usually added, 0.5 degrees - 1.0 degrees is enough to avoid big pH swings.

this will result in a pH of 7.1 - 7.2.

What are you referring to as hardness of 10? General hardness or carbonate hardness? and why 10?

 

RO water tested for pH over 96 hours, exposed to the atmosphere never moved from 6.25. It doesn't have any buffering capability so a little KH is usually added, 0.5 degrees - 1.0 degrees is enough to avoid big pH swings.

this will result in a pH of 7.1 - 7.2.

What are you referring to as hardness of 10? General hardness or carbonate hardness? and why 10?

Thank you for the help. I'm a bit overwhelmed with the water stuff.

I THINK I'm referring to General Hardness. When I was researching fish, they always give a preferred pH and a preferred hardness but none of the research places distinguish between KH and GH when they make that recommendation for the fish. So I think it is GH. I chose 10 because that number seemed to fit most of the fish I am looking at -- various tetras, cories, peacock gudgeon, bolivian ram, snails.

 

I THINK I'm referring to General Hardness. When I was researching fish, they always give a preferred pH and a preferred hardness but none of the research places distinguish between KH and GH when they make that recommendation for the fish. So I think it is GH. I chose 10 because that number seemed to fit most of the fish I am looking at -- various tetras, cories, peacock gudgeon, bolivian ram, snails.

For 100% RO water, the cheapest and easiest way to get desired parameters would be as follows:

KHCO3 - For KH - 0.5 - 1.0 degrees is good, I recommend 1.0 degrees. This will give you a pH of 7.1 - 7.2.

CaSO4 - For GH (Calcium) - 6-8 degrees total is a good starting point, 4-5 degrees should be from CaSO4 (or about 30ppm Ca).

MgSO4 - For GH (Magnesium) - 6-8 degrees total is a good starting point, 2-3 degrees should be from MgSO4 (or about 10pm Mg).

Head over to Rotala Butterfly | Planted Aquarium Nutrient Dosing Calculator and punch in your water volume, select DIY, punch in your compound (For CaSO4 there are multiple options, pick the 1/2H2O option). Select "dose to reach target" and punch in your target, it will tell you exactly how much of each compound to add into how much water to reach your desired goals.

If you want GH a little higher than 6-8, that's fine, just keep the Ca:Mg ration roughly 3:1 (so for a GH of 10, 7 degrees from CaSO4 and 3 degrees from MgSO4).

 

Thank you. I will look through all of this and try and process it all. Appreciate your help!

 

Thank you. I will look through all of this and try and process it all. Appreciate your help!

Feel free to ask any questions if you need to!

 

Mix rodi with your water you have

 

Mix rodi with your water you have

OP's tapwater is extremely inconsistent, which is why they are making the switch to RO water. Mixing inconsistent tapwater with RO = inconsistent / fluctuating water for the tank (water changes).

 

You could test your water and when it’s good use it when it isn’t good use rodi?

 

You could test your water and when it’s good use it when it isn’t good use rodi?

This would increase the risk for swinging parameters / inconsistencies.

Always using RO water and remineralizing it to the exact same parameters each time = complete stability and no risk for fluctuating parameters = peace of mind knowing exactly what's in the water each time.

 

You could test your water and when it’s good use it when it isn’t good use rodi?

My tap water isn't safe as it swings wildly with rains, various chemicals added and removed, sometimes surface water is the source and sometimes well water is the source. And a few times a year the surface water "turns over" and creates another issue as well. I need to be consistent and just use treated RO water to maintain consistency and accuracy. Thanks!