Carbonate hardness

Roman

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Jan 23, 2005
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My tap water is 12°dKH.

When I do weekly 50% water change it goes down to about 9 degrees which is consistent with about 6 degrees before water change. This is in one of those small, high light, CO2 tanks. About 55L (15G), 3.6 WPG (3*18W of FL with reflectors), very high plant biomass (check the picture in my gallery :D ).

Now, what I'm wondering :confused: is, is it possible to hit Ca or Mg deficiency with that carbonate hardness?
 

Gill Man

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Feb 10, 2005
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Re: Carbonate hardness

I'm not sure how your dKH is changing other than if you were using very soft water to cut it with. As for a calcium or magnesium deficiency, you need to also check the value of your dGH. Ca and Mg are not related to dKH.
 

Roman

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Re: Carbonate hardness

Maybe I jumped with the conclusion about KH being used by plants. It's about 6 degrees before water change and it was like that for some period of time, but I measured tap water just recently. Need to do some more consistent tests to see what's going on here.
Those snails are eating my carbonates at night :D

General hardness was usually 2-3 degrees higher than carbonate hardness, but then again I didn't measure that one for ages. I'll buy a new test and use it once or twice and find what I probably know or doesn't matter anyway.

Yes, Ca and Mg are related to GH, my bad :eek:

But let we say theoretically that dGH is 14°, can I get Ca or Mg deficiency. If there would be only Ca ions or only Mg ions...is it possible?
 

Laith

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Re: Carbonate hardness

Theoretically it is possible. My tap water here is at a GH of 15 but according to the water report, has very little Mg in it. So instead of the "usual" 3 or 4:1 Ca to Mg ration, mine is like 12:1.

Therefore I add Mg to my tank.

However, as far as I have heard, this is rare and usually if your GH is above 6 or 7 (some say 5) then you'd have enough Mg and Ca.
 

Roman

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Re: Carbonate hardness

The reason for asking this is here: Nutrient deficiency

I did grow Nesaea much, much better in the past when I didn't know much about fertilizing and stuff, ironically. I know what kind of symptoms belong to lack of main macro-micro nutrients, but then again they all look similar to me. :confused:

I'm trying to eliminate elements one by one and my latest suspect is that something is missing or is not sufficient in my micro-nutrient fertilizer for which I don't know all quantities of elements in it. I tried dosing more, but the results were not satisfying, so something must be missing. In general plants doing fine but I know for sure they could do better, so please help me get my sanity back :)

There is enough N, P, K should be sufficient (some from fertilizer and some from KNO3), Ca & Mg from tap water (it's hard)???, Iron (from fertilizer - if the info on quantity I got is true, then it should be sufficient)???.

Boron ???

Btw, I ordered CSM from Greg, so maybe this will solve the problem when I get it, but I still want to pinpoint the problem.

Main suspects for the moment are Iron and Boron.
 

m lemay

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Jan 23, 2005
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Re: Carbonate hardness

Laith said:
Theoretically it is possible. My tap water here is at a GH of 15 but according to the water report, has very little Mg in it. So instead of the "usual" 3 or 4:1 Ca to Mg ration, mine is like 12:1.

Therefore I add Mg to my tank.

However, as far as I have heard, this is rare and usually if your GH is above 6 or 7 (some say 5) then you'd have enough Mg and Ca.

This situation isn't as rare as you might think. I ran into an Mg deficiency in my tank but with a slightly different situation. My tap water is
 

Tom Barr

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Jan 23, 2005
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Re: Carbonate hardness

Well, it's rather a simple process to rule out deficiencies.
Simply add more of he suspect beyond a limiting level.
A smidge of Boric acid, 1/8" teaspoon of Epsom salt, and a bit more General trace fert will do it.

But as a poster already noted, CO2.

When the KH moved around, you have a CO2 issue (as a rule).
Why would a plant bother with using HCO3, when it could get plenty of CO2?
(Very) Probably because you are not adding enough CO2.

Regards,
Tom Barr