how much epsom salts in a solution when using EI?

[jarthel]

I was reading theplantedtank.co.uk and Jame never mentioned how much epson salt is required. I know one of the mods mentioned in the the tutorial but I prefer making a solution just because I believe it's easier to handle.

so how much epsom salts is required? I've searched the net and forums but came away empty-handed.

thank you very much
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off-topic questions
1. when using powder dosing, do you put the powder into the tank directly? thanks again

2. EI solution and EI powder dosing, are they really the same? it seems to my inexperienced mind that powder dosing puts more nutrients compared to the solution?

thank you

 

[Mortis]

I use an amount equal to about quarter the amount of KNO3

 

[plantbrain]

If you add about 2-3ppm of Mg per week, things are fine for most tanks.
A dosing calculator will tell you the rest.


Regards,
Tom Barr

 

[chump54]

check out cegs article it'll give you the confidence to do it and has info about mg in it too

http://www.ukaps.org/EI.htm

Chris

 

[dw1305]

Hi all,
You just need to remember that "Epsom Salts" (and most commercial sources of magnesium sulphate) are the "hepta-hydrate" form = MgSO4.7H2O (there are 7H2O the "water of crystallision")

This makes a lot of difference to the amount of magnesium in the compound.

Anhydrous MgSO4 contains 20% Mg (RMM 120.3)
(Mg) 24.3 + (S) 32 + O4 (16 x 4) = 56.3 + (64) = 120.3 and (24.3/120.3) = 20% Mg.

Whereas "Epsom Salts" MgSO4.7H2O has only 9% (RMM 246.3):
(Mg) 24.3 + (S) 32 + O4 (16 x 4) = 56.3 + (64) = 120.3 + 7 x H2O - 7 x (1+1+16 = 18) = 126
126 + 120.3 = 246.3 24.3/246.3 = 9% Mg.

Plants don't require a great amount of magnesium, so "James C's all in one solution" http://www.theplantedtank.co.uk/allinone.htm adds only 0.2 ppm Mg to the tank (and he used magnesium sulphate heptahydrate to make up the solution).

cheers Darrel

 

[plantbrain]

Adding 10-50X the 0.2ppm amount also poses no adverse effect on any species either.

Actually having tested it in a number of aquariums and a number of years...........


Regards,
Tom Barr

 

[dw1305]

Hi all,

Adding 10-50X the 0.2ppm amount also poses no adverse effect on any species either.

Yes, without James' solution I would have suggested 5 - 10ppm as the range to aim for, it makes little difference to the plants how much there in solution, once it is non-limiting. Hydroponic tomatoes, for example, are grown at much higher magnesium levels (ideally above 50ppm).

Some soils and waters will be naturally very high in magnesium, in the UK we have soils on the Lizard peninsula (derived from the rock "Serpentine"), and they are calcium poor, but magnesium rich and grow a very strange mix of plants with some "lime" loving plants (that can substitute magnesium for calcium) like Dropwort (Filipendula vulgaris) and Kidney Vetch (Anthylllis vulneraria) growing with calcium "hating" plants like Heather (Calluna vulgaris), as well as Cornish Heath (Erica vagans) which is restricted to the serpentine soils.

cheers Darrel

 

[chris1004]

Hi,

Whilst I agree entirely with the above comments about just being certain that there is an unlimited ammount of Mg availble to the plants its worth bearing in mind that if your tank waters hardness is important to you (i.e. the GH) an excess of Mg will raise the GH.

GH (or general hardness) is a measure of the calcium + the magnesium content of the water. Ideally there should be a ratio of around 3or4-1 calcium to magnesium. As far as the plants are concerned as long as both the Mg and the Ca are non limiting then for most plant species this is fine. Things only become a little more tricky with soft water loving species of both flora and fauna as the margins for error are far less.

At least thats the way I understand it.

Regards, Chris.

 

[chris1004]

1. when using powder dosing, do you put the powder into the tank directly? thanks again

Yes you can, or you can make up a solution to suit.

2. EI solution and EI powder dosing, are they really the same? it seems to my inexperienced mind that powder dosing puts more nutrients compared to the solution?

thank you

Yes they are really the same its just two different delivery methods thats all. Making a solution just makes things easier to dose. For arguments sake if you were making a 4 week supply and dosing 1 teaspoon 3 times a week then you would put 12 teaspoons into the initial solution to be fed to the plants in twelve equal parts therefore still dosing exactly the same quatity. Although initially it can sound complicated making a solution enables the user to deliver all of the required dry powder ferts in a pre disolved format (aiding better and more even ditribution) with just one application per dose instead of upto maybe 4 dry powders measured out each time. It doesn't matter how much water you use to make up the dose either but for a 4 week supply 600ml usefully divides by 12,(3x 50ml doses per week x 4 weeks). Your not restricted to making up 4 week supplies either. Whatever suits you really.

Regards, Chris.