# RO water re-mineralization recipe for just 1 gallon?



## Verde (Mar 2, 2015)

Hi All,

Does anyone have an ro water re-mineralization recipe for just 1 gallon?

I’m going to try the Walstad Method (again) in a 5 g. tank. Although, after adding the substrate, etc. there will probably only be 3-3.5 gallons of water in there.

The water here is terrible- PH 9+, GH and KH are both 0. It has just given me fits with past tanks, so I thought this time it is ro (with a little tap cut in) or nothing.

I thought I would use food grade calcium carbonate for the Ca, Epsom salts for the Mg & S, and salt substitute or potash for K. 

Substrate- MG organic choice
Plants- Whatever survives! I’m going to try Crypt Wendtii green, marsilea crenata, staurogyne repens ,hygrophilla difformis, moss ball, and some terrestrial plants as emergents with their roots in the water
Lighting- 6 watt led and an East window
Heating- 50 watt submersible 
Fauna- Eventually 1 betta and some snails

Thanks to everyone for any help!


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## Verde (Mar 2, 2015)

Hi All,

Does anyone have an ro water re-mineralization recipe for just 1 gallon?

I’m going to try the Walstad Method (again) in a 5 g. tank. Although, after adding the substrate, etc. there will probably only be 3-3.5 gallons of water in there.

The water here is terrible- PH 9+, GH and KH are both 0. It has just given me fits with past tanks, so I thought this time it is ro (with a little tap cut in) or nothing.

I thought I would use food grade calcium carbonate for the Ca, Epsom salts for the Mg & S, and salt substitute or potash for K. 

Substrate- MG organic choice
Plants- Whatever survives! I’m going to try Crypt Wendtii green, marsilea crenata, staurogyne repens ,hygrophilla difformis, moss ball, and some terrestrial plants as emergents with their roots in the water
Lighting- 6 watt led and an East window
Heating- 50 watt submersible 
Fauna- Eventually 1 betta and some snails

Thanks to everyone for any help!


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## Tugg (Jul 28, 2013)

After using RO for a bit, I can't stand the idea of tap water anymore. With such a small tank, just go with the remineralized RO. I'd skip the tap all together.

Calcium Carbonate will not dissolve quickly/well. It's virtually insoluble (why corals use it for a skeleton). What happens is that it neutralizes acid and become Calcium Bicarbonate.. which is highly soluble. This will buffer/raise the PH over time.

Most people use Sodium Bicarb (baking soda) for the kh. I prefer Potassium Bicarb though for planted tanks. I'm sure more than enough sodium is in the fish food.

For the GH, the easiest way is to just use Seachem Equalibrium. It's a blend of K, Mg, and Ca Sulfates. You could just buy those salts and do it yourself too though. Its just more math.


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## Tugg (Jul 28, 2013)

I saw you had posted this thread twice, I've deleted the El Natural one since this is more about water than the setup style.


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## Verde (Mar 2, 2015)

Thanks for your reply 

"Calcium Carbonate will not dissolve quickly/well. It's virtually insoluble (why corals use it for a skeleton). What happens is that it neutralizes acid and become Calcium Bicarbonate.. which is highly soluble. This will buffer/raise the PH over time."

Does that mean the Kh in that water would test higher if given more time to dissolve? I waited about an hour before testing it last time, should I wait like 24 hrs instead?

I've had bad algae experiences dosing Equalibrium in past Walstad attempts (there have been many), so I wanted to try to put only the bare minimum back into the RO water and hope the nutrients in the soil will supply the plants with most of what they need.

Potassium bicarbonate sounds really interesting. Would it raise the PH? The Calcium carbonate I put in raised the ph _so_ much!

What do you think about trying potassium bicarbonate, calcium sulfate, and Epsom salt? Calcium sulfate is really hard to dissolve though, right? Is that too many sulfates?

Thanks again for your help, I really wanted a planted tank to work this time!


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## Bloomer (Jan 12, 2015)

Here's what I do, not much info on this for some reason, RO is so easy to customize, I'm not sure why more hobbyists don't use it.

I use 4 gal buckets that hold 3 gals easily, so this is based on 3 gals of RO.

For softer water, GH about 100 ppm, pH 7, KH 3:
1/4 tsp calcium chloride
1/16 tsp mag sulfate
1/16 tsp Seachem Alkaline Buffer*
1/32 tsp KCl

For harder water, double the CaCl2 and Mag sulfate, gives GH about 200 ppm. You should test to see what you end up with, ratios should be set by mass, not volume, but they're not particularly critical, Ca/Mg should be 3-4/1. All my additives are powder except the CaCl2, which is pellets.

* Alkaline Buffer appears to be Sodium Bicarbonate, it has no effect on GH test results even if it's dumped into a small container of water, indicating no calcium. 

You can try using some Equilibrium, plants will look better, but the sulfur in it isn't liked by my tanks and algae becomes a problem. I use root tabs once in a while if indicated, not regularly, though; no liquid ferts. 

You could use calcium carbonate as a calcium source, but it will jack pH very high if high hardness is the goal. Definitely experiment with that. 

I've been keeping 25 or so planted low tech tanks with this recipe and it has worked well, fish range from apistos and angels to mollies. Growing nice plants, lots of red ones is no issue at all. 

I got this from Ecology of the Planted Aquarium, pg 87. Best book ever. 

Seems like you're running into the same issues I did.


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## Verde (Mar 2, 2015)

Thank you!! I'm going to try this as soon as I can find the CaCl2 
Is there a best way to measure 1/32 of a tsp?


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## Tugg (Jul 28, 2013)

A lot of dry dose people use these:

http://www.amazon.com/Libertyware-Smidgen-Pinch-Measuring-Spoon/dp/B002X9I4RC


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## Verde (Mar 2, 2015)

Wow, thanks Tugg


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## kekon (Aug 1, 2005)

> "Calcium Carbonate will not dissolve quickly/well. It's virtually insoluble (why corals use it for a skeleton).


It will dissolve in water enriched with CO2. To make CaCO3 dissolve faster one needs to grind it with a mortar so it will take the form of extremely fine dust. Typical (non ground) CaCO3 settles on the bottom of the tank when poured into it and it will take long time to dissolve. Ground CaCo3 will float in the water and it will dissolve much faster. Obviously to grind CaCo3 can be tedious if there is big amount of it.


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