How to calculate PH lowering? (Citric acid)

[Megas]

You have Citric acid to lower Ph
You have a container 10L (2.64 Gallons)
Your waters PH is between 7.25 to 8.05 units

In order to get to around 5.8 or so how much citric acid would I have to add?

As it is in crystal form trying to figure this out per tsp


Is there any general rules of thumb for this?

 

[Hydro-Soil]

Personally I would make life easier on myself....

Go to the local Rx shop and get an eye-dropper bottle... should be less than $5. One with a glass dropper would be preferred.

Drop a tsp of your powder in, fill it with R/O or distilled and shake till clear.

Use a few drops and check the pH change.

Later on, get a grain/powder scale and measure out your starting teaspoon so you can get the same concentration each time.

This also works with super concentrated liquid pH up/down... just add a dropper or three of the liquid and fill the rest of the way up with water. Fun.

Stay Safe!

 

[pinecone]

You have Citric acid to lower Ph
You have a container 10L (2.64 Gallons)
Your waters PH is between 7.25 to 8.05 units

In order to get to around 5.8 or so how much citric acid would I have to add?

As it is in crystal form trying to figure this out per tsp


Is there any general rules of thumb for this?

Someone else suggested this idea and I think it is a good one. Get a quart container and fill it with RO. Take a teaspoon of citric acid and dissolve it in the container. Now when you want to pH down use a bit of the concentrated solution from the quart container. This way you won't have deal with working with small amounts of the powder and you will have a consistent solution.

Pine

 

[foomar]

Tap water here is always above pH9 , use citric acid in home brewing and have tried it several times to adjust for growing in soil when i run out of rainwater.

Would make up a stock solution as suggested , 10g or two teaspoons per litre , its a weak acid and it takes quite a lot.

The maths to work out a required amount are not simple , easier to measure the pH by meter as you add it , will usually stick at 6.5 then drop straight to 4.5 with only a few drops more , takes a while to stabilise.

Works good enougth in soil , not so sure in hydro if a lot of citric was required , some defficiency issues with mg and boron.

Its used as a buffer in many nutes already , it chelates metal ions and effectively locks them out , have had enougth problems to use another acid in preference in a res system.

Trying to mix nutes in proved a nightmare , swinging pH would not settle down and was at 6.5 mostly with some confused plants.



Your supply water pH is much lower than mine , and you might not have the same issue , lots of lime in my supply and nitric acid is a better option here.

 

[Megas]

Whats RO stand for?
I just don't want to toss in weird chemicals to lower my ph. I'm open to other options?

 

[pinecone]

It is shorthand for reverse osmosis water (RO). Reverse osmosis water is basically water with all the mineral content removed so there is no buffering capacity.

Pine

 

[exploziv]

reverse osmosis. it's a type of filtering method.
pure water, no chems there.

 

[foomar]

The RO units marketed to aquarium folk are a good option , cheapest per litre if you need volume , inexpensive longterm solution if your water is bad enougth to warrant it.

Only downside is they waste 3 - 5 times as many litres as they purify , and require a decent mains pressure or additional pump to work fast.