how do you concern about Ca and Mg dosage ?

[dx]

I have read people dosing K, NO3 and others as fertilizer in planted tank, but don't remember seeing people talking about Ca and Mg here. Ca can be introduced thru coral chips. Some recommend Ca 20~40ppm and Mg 10ppm.
My questions are:
1) how do you control Ca concentration, is it by calcium carbonate and / or calcium sulphate ? Calcium carbonate is almost insoluble in water though.
2) if Ca 40ppm and Mg 10ppm is achieved, I guess the hardness would be moderately hard. Will this affect fishes like ram, clown loach, kuhli loach and other soft water fishes ? I came across in a book saying that "don't add Ca and Mg salt" when keeping clown loach.
I am more concern about question 2)

[PeterGwee]

Its fine...don't worry. As long as you don't add too much in the initial stages and allow them to acclimatize, they are fine with it. Just do it slowly and bring up the levels if your plants are showing lack of Ca or Mg.

[juggler]

There was a good discussion on this in the some time back. See http://www.aquaticquotient.com/phpbb...ic.php?t=10319

Basically, if you do frequent large water changes, the tap water can help to replenish the Ca and Mg in your tank. You may wish to dose extra if your plants really need it.

I used to have discus, clown loach in water that's quite hard (11 dkH, ? dgH) and alkaline (7.4~7.6) because of my coral chip substrate. They lived.

[theodore]

This is from a post by BC in another forum (dunno if it is the same guy we have here in AQ) :

1 ppm Ca is equivalent to 2.5ppm CaCO3 (~0.14°GH)
1 ppm Mg is equivalent to 4.2ppm CaCO3 (~0.23°GH)

[PeterGwee]

17.9ppm = 1dGH

[vinz]

Dose these 2 only if Mg or Ca deficiencies show up. Some tanks seem fine without extra Mg, Ca, others don't.

[vinz]

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On 9/18/2003 11:19:18 AM

17.9ppm = 1dGH
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That should be 17.9ppm of CaCO3 = 1dGH. I think it's approximate, but good enough for our purposes.

[bttay]

Is it correct to say that dosing Calsium Sulphate will not change the GH while dosing Calsium Carbonate will?


Thanks.

[vinz]

Calcium sulphate will raise GH. GH in our water is mainly caused by Calcium and Magnesium. Calcium carbonate will raise both GH and KH. KH is carbonate hardness.

[geoffrey]

If you change water regularly, you may not need Mg and Ca. I dose them because I change water fortnightly and I believe what comes from the GH by the end of the 1st week may not suffice.

Do dose Mg carefully in my opinion. If fact, I dose very little. There is a discussion in AB on K:Ca:Mg relationship that may interest you. It says too much Mg and K may not be heathy.

[juggler]

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On 9/18/2003 1:53:24 PM

If you change water regularly, you may not need Mg and Ca. I dose them because I change water fortnightly and I believe what comes from the GH by the end of the 1st week may not suffice.


Do dose Mg carefully in my opinion. If fact, I dose very little. There is a discussion in AB on K:Ca:Mg relationship that may interest you. It says too much Mg and K may not be heathy.
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I think should be "...too much Mg and K in relation to Ca may not be heathy". Right?

[bclee]

GH is the measure of Mg++ and Ca++ ions in the water. 1°GH is equals to 17.9ppm equivalent of CaCO3.

1 mole of Ca++ or Mg++ is equivalent to 1 mole of CaCO3.

Molar wt:
Ca - 40
Mg - 24
CaCO3 - 100

Therefore,
1 ppm Ca is equivalent to 2.5ppm CaCO3 (which in turn = 0.14°GH)
1 ppm Mg is equivalent to 4.2ppm CaCO3 (which in turn = 0.23°GH)

IME, fishes are not too concern about high GH. I keep Rams and cardinals in my tank with water of 15°GH (dun ask me why... ). No problem at all.

As for too much Mg or K affecting Ca uptake, I have not experience that too. I dose a lot of K, maybe up to 50~60ppm a week. No Ca uptake problem in my plants.

I dose Mg & Ca in the form of Seachem Equilibrium (contains Ca, Mg, K, Fe & Mn). I raise about 3°GH in the tap water every time I change water (maybe more due to miscalculation... which resulted in my high GH water[:] ).

BC

[geoffrey]

Right : )

[bttay]

Talked to Dr. Mallick this afternoon. He said that Calsium Sulphate and Calsium Carbonate make water cloudy (if I got his message correctly). He recommended Calsium Nitrate.

[bclee]

This is because CaSO4 & CaCO3 are relatively quite insoluble in water.

BC

[bclee]

CaCl2 is very soluble... BTW.

BC

[PeterGwee]

Mmmmmmmm...it seems that high GH provided Ca and Mg are proportional along with high K does not cause Ca deficiencies seen with distorted leaves. I tried the Seachem equilibrium "new" formula and found my hygro sunset "new" leaves start to distort and die off.....I added Seachem reef complete to raise Ca and the symptoms seem to went off after that...I would monitor the situation further before coming to a conclusion that high K can drive high Ca/Mg uptake such that particulary Ca deficiencies can show up if not supplement.

[dx]

thanks so much you guys for the feedback
i have got my answers and also got extra knowledge from here. Great !!![] []

[geoffrey]

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On 9/18/2003 7:33:37 PM

Mmmmmmmm...it seems that high GH provided Ca and Mg are proportional along with high K does not cause Ca deficiencies seen with distorted leaves. I tried the Seachem equilibrium "new" formula and found my hygro sunset "new" leaves start to distort and die off.....I added Seachem reef complete to raise Ca and the symptoms seem to went off after that...I would monitor the situation further before coming to a conclusion that high K can drive high Ca/Mg uptake such that particulary Ca deficiencies can show up if not supplement.
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It is not K driving up uptake of Ca. According to the discussion in AB by Roger Miller, in the K:Na:Mg:Ca relationship, plants have the highest affinity for K, follow by Na then Mg. Ca the least. Hence if there is far too much K or Mg in relation to Ca, K and Mg out-compete Ca in plants uptake.

[PeterGwee]

But I know Tom barr don't think so...he and his folks at SFBAAPS dose loads of K up to 50ppm or more with high or low GH and does not experience anything like this...

I continue my K dosage only to up my Ca through dosing of seachem reef complete and the Ca like deficiency symptoms went away...I do doubt the high K blocks certain nutrient theory as that applies to terrestrial plants based on certain studies carried out.