# [Wet Thumb Forum]-Proper Ratios for Ca:Mg



## Justin Fournier (Jan 27, 2004)

Hi all,

Quick question. I have very low GH in my tap water, basically 0. So I need something to increase my GH. I bought some Magnesium Sulphate (Epsom Salts) and some Calcium Chloride (Kent's Liquid Calcium). I want to bring the GH up to maybe 4-6 range, but not sure the exact method to go about getting the proper ratios of Calcium to Magnesium. My tanks is 75g BTW. TIA!


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## Justin Fournier (Jan 27, 2004)

Hi all,

Quick question. I have very low GH in my tap water, basically 0. So I need something to increase my GH. I bought some Magnesium Sulphate (Epsom Salts) and some Calcium Chloride (Kent's Liquid Calcium). I want to bring the GH up to maybe 4-6 range, but not sure the exact method to go about getting the proper ratios of Calcium to Magnesium. My tanks is 75g BTW. TIA!


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## Stevenl (Mar 31, 2004)

I actually use the same things (liquid calcium and epsom salts) to increase the gH of our local water. The Ca:Mg ratio should be 4:1
40ppm of liquid calcium and 10 ppm of epsom salts should give a gH of 4.


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## EDGE (Feb 28, 2004)

How much liquid calcium do you dose every day? week? I may have to go with this route to get my gH back up

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
Mike's Canadian Aquatic Plant Page
A Canadian's Plant Traders website


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## Justin Fournier (Jan 27, 2004)

Thanks Steve,

How did you actually figure out how much of each to use? Not volume I am assuming?


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## EDGE (Feb 28, 2004)

I read from the instruction on Kent marine that 5 ml/1 capful gives around 400 mg/l per 50 gallon. so thats 40 ppm?

you can figure out epsom salt dosage requirement from the Chuck's calculator

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## Justin Fournier (Jan 27, 2004)

I was told 400mg/l = 400 ppm. well I was told 1mg/l = 1ppm. Not sure if this is accurate.


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## Roger Miller (Jun 19, 2004)

Justin604,

In fresh water ppm and mg/l are the same thing.

EDGE,

I read the Kent site to say that 400 mg/l is their recommended maximum level. They don't say that a capfull/50 gallons will give 400 ppm. The actual level that you would get in a reef tank from any given amount of calcium depends on how quickly the critters are using the calcium. So they don't give dosing levels. Instead, they recommend a good test kit.


Roger Miller


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## EDGE (Feb 28, 2004)

Do you think 2.5 ml of liquid calcium + 1 teaspoon of epsom salt be enough if I dose every 3-4 days after water change?

Is 2.5 ml way too much calcium? I don't want to invest in another test kit.

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## EDGE (Feb 28, 2004)

I justed test the gH in the water.. it shows 3.43 gH.

I used the hagen test kit.. 3 drop to change color x 2 to get gH. x 0.056 to get dH = 3.43.

humm. thats a huge jump in gH from 0.

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## Justin Fournier (Jan 27, 2004)

What exactly did you do to get that much Gh? I have a 75 as well, Just getting the water parameters straight before I get the plants.


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## EDGE (Feb 28, 2004)

I use 100% r/o water so calculation could be the same as yours. I just added 2.5 ml liquid calcium and 1 teaspoon of epsom salt. It just went up to 3.43 gH or dH or whatever u want to call it from initial testing of 0 gH or dH.....

I am going to change it to weekly dosage instead of 3-4 days though. From the other question I asked, that could cause an overdose in such a short time.

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## Justin Fournier (Jan 27, 2004)

how certain are you that the 4:1 Ca:Mg is right?


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## EDGE (Feb 28, 2004)

I am not sure, You will have to wait for StevenL reply on that one.

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## ekim (Jan 31, 2004)

You guys are not doing the right calculation for that product, as Roger has mentioned!

2.5ml of that product is not much Ca, but that really depends on your tank size!

I think 2.5ml will add about 6ppm of Ca to a 10 gallon!!


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## EDGE (Feb 28, 2004)

I got a jumped of approx 3.43 dH.

Does that mean I have too much Mg?

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## ekim (Jan 31, 2004)

without knowing much info I would say yes!
What tank size? 75G?
I wouldn't say you addded to much Mg to your tank, but you may have more Mg than Ca!

Here is a post to help you figure out how much of "kent's liquid Ca" to dose!

http://aquabotanicwetthumb.infopop.cc/groupee/forums?a=tpc&s=4006090712&f=9156020792&m=8716094092&r=6786038092#6786038092


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## EDGE (Feb 28, 2004)

humm. approx 11 ml to get it up to 30 ppm for 10 gallon.

Is there a source of cheaper Ca? going through a bottle of liquid cal in a month gets pretty expensive.

75 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website


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## ekim (Jan 31, 2004)

edge, I don't think it's very important to get 30ppm of Ca, it is probably more important that the Ca to Mg ratio is good.

like 12ppm of Ca to 3ppm of Mg for example!

Roger, please correct me if i'm wrong on this!

Thanks


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## Roger Miller (Jun 19, 2004)

I think 30 ppm calcium is a good target, but lower and higher values are certainly acceptable. 

The plants seem to be pretty accepting of a range of Ca:Mg ratios. The only hard-and-fast limit I've read is that magnesium should not exceed calcium. I'm pretty sure that even that has some give. My favorite hydroponics source advises a Ca:Mg ratio of 2:1 in nutrient solutions. There is a long-standing recommendation to use a ratio of 3:1 in aquariums and 4:1 is fine, as well.


Roger Miller


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## Justin Fournier (Jan 27, 2004)

I think what I am going to do is add the liquid calcium till I get a reading of 3 gh then add magnesium sulphate will I get one, giving me a 3:1 ca:mg. How this will work lol


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## Justin Fournier (Jan 27, 2004)

Well after a few days of mucking around with Calcium Chloride (Kent's Liquid Calcium) and Magnesium Sulphate (Epsom Salts) here is what I have managed to do.

Starting with 0 gh 0 kh

1mL Liquid Calcium per 2 gallons of water have me a GH of 4.5-5, kh 0.

1mL Epsom Salts, Used the lid from the calcium bumped my gh to 6.5-7, 0kh

This give me a ratio between 3:1 to 2.5:1. 

This is accebtalbe from what I have read, and is very easy to work with, in comparison to 4:1 where you borderline on a Mg shortage. HTH.


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## EDGE (Feb 28, 2004)

Justin, how much are you dosing in your 72 gallon now? I could use some help to balance out the nutrients. When you say 1 ml of epson salt is that the dry dose amount?

If I dose 2 cap of calcium and 1/2 teaspoon of Mg. would that be enough?

72 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website

[This message was edited by EDGE on Sun July 27 2003 at 09:38 AM.]


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## Anthon (Feb 26, 2004)

I think that your Ca:Mg ratio is OK but your KH not. KH smaller than 3 involve risks of high pH fluctuation.

You can increase KH using CaCO3 (which increase GH and KH); around 1 tsp / 200 L to increase GH and KH of 1Â°

You can also increase your KH without increasing GH by adding NaHCO3 (1tsp/200 L to increase KH of around 1Â°)

_____________________________
Sorry for my bad english ...


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## EDGE (Feb 28, 2004)

Where can I get CaCO3?

72 Gal, 3 WPG PC 10 hour, pressurize co2 /w controller 1 bps, Fluval 404, ph 6.8
A Canadian's Plant Traders website

[This message was edited by EDGE on Sun July 27 2003 at 03:10 PM.]


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## Rex Grigg (Jan 22, 2004)

Try a home brew/wine making shop.

Moderator










American by birth, Marine by the grace of God! This post spell checked with IESpell available at http://www.iespell.com

See my Profile for tank details.


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## James English (May 16, 2003)

Just a quick question,i just had a look at my tap water parameters from the water company here in the uk and they quote a calcium figure of 94.7 mg/l and magnesium figure of 10.7 mg/l what do make of that? Is this calcium figure sky high or normal?


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## Anthon (Feb 26, 2004)

The ratio Ca:Mg of your tap water depends on the nature of the soil of your area.

I live in an area where soil is Ca rich and Mg poor. My tap water has 75 ppm Ca and 3 ppm Mg. I simply use reverse osmosys water to decrease my KH and GH to 4 and then add MgSO4 (epson salt) to increase Mg rate.

_____________________________
Sorry for my bad english ...


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## James English (May 16, 2003)

I can't use RO water due to rented accomodation, so is having calcium so high going to cause any trouble?


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## James English (May 16, 2003)

Can anyone answer the question? Does having a high calcium content affect the plants in any way?


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## perrush (Feb 24, 2003)

@ James :

As said here, it would be better to have a 3:1 ratio and have a little less Ca BUT I don"t think yout plants won't grow.

First make sure you have proper NPK levels (NO3/PO4 and K) and the you have enough light (=energy) en CO2 (carbon source). If things still don't work than, then you can look further (at Fe levels and eventually the Ca and Mg)

hope this helps a little

--
English isn't my native language, but I guess you already noticed that ))
--

Perrush


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## Justin Fournier (Jan 27, 2004)

Sorry for not posting earlier. I am dosing as I said earlier in the post.


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## Justin Fournier (Jan 27, 2004)

O after reading my mg dosing, I think that is not right. I am sure I am dosing more then that. I used Chucks calculator.


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