# Ca:Mg and K2SO4



## trong (Aug 8, 2006)

yesterday i was reading some posts and noticed different grades of ferts used in making PPS-Pro and it occured to me the grade of K2So4 i use is called agro grade. It says on the package 0-0-50! Does this weigh out the same as lab grade? My lamotte K test kit says im at about 10ppm, but some of the plants show tiny pinholes in them occasionally(hygrophila sp asian) and sometimes (alternanthera rosaefolia) mostly in the older leaves. Could i have a problem developing? Ive only been using pps-pro for about 2+ months. 
80 gal, 4 watts per gal, 10hrs a day, Co2 injected, heavilly planted with above average fish load.
NO3 10-15
P 1.5+
K 8-10
Kh 2
Gh 5
te .1 -.15 
1/3rd water change weekly using r/o with gypsum for ca to 20ppm


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## Glouglou (Feb 21, 2006)

*Re: K2So4*

For the pinhole you can go to around 25ppm potassium.
personally I find your Nitrate and phosphate reading a little bit high
I prefer around 5ppm nitrate and .3 phosphate


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## Edward (May 25, 2004)

*Re: K2So4*

I don't see anything wrong, you are doing it right. Four questions; what kind of substrate, how much CO2, what kind of light and what is the gypsum?


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## trong (Aug 8, 2006)

*Re: K2So4*

thanks for your response. my substate is 6 yr old flourite mixed with inert gravel. i keep co2 at 30ppm. the light is a mix of t-5 t-8 and vho which i'm phasing out after my bulbs need replacing(soon). gypsum, is a soil amendment designed to break up clay in your yard. also called (CaSO4)2.H2O On a side note thanks again for the fertilator. it's so helpful for making the water just how i want it. I've been fiddling around in this hobby for about 7 yrs and it's made my hobby time more accurate and enjoyable


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## Glouglou (Feb 21, 2006)

*Re: K2so4*

sorry to change subject but wath 's the reason to phase out you VHO?


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## Edward (May 25, 2004)

*Re: K2so4*

Hi trong
Different grades of K2SO4 are always acceptable K2SO4, but generic names like gypsum can mean anything and may cause problems. Also check your aquarium water for Ca and Mg. Your 20 ppm Ca makes 3 dGH, not 5. So what is the extra 2 dGH? 

Maybe you are pushing your plants too much with the high CO2. Lowering it to 20 ppm won't kill anything. You may actually grow nicer plants. 

The Fertilator is a great tool, glad you like it.



Thank you
Edward


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## trong (Aug 8, 2006)

*Re: K2so4*

thanks again for replies. I'll be phasing them out for more lumens per watt with more t-5's.
On the bag saying gypsum it say (CaSO4)2H2O and thats the chemical makeup of whats inside bag right? I used aquarium pharmaceutical Gh kit and Salifert Ca test kit. I believe my Mg is around 9.6ppm. As for the other 2dGh you refer to, i'm not sure what you mean. But i am curious,to me it's moments like these that often lead to profound breakthroughs in learning for me. 
It is my understanding the If my dGh is 5 and my Ca is at 20ppm my Mg would be 9.59ppm. Am I wrong? If so please help me out cause i am really lost. Thanks I look forward to your replies


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## Edward (May 25, 2004)

*Re: K2so4*

Hi trong
The CaSO4 product should be ok if it doesn't contain any other additives like fungicides and so on. Many dry construction products do. 

The Ca : Mg ratio of 4 : 1 is usual across North America and Europe. But most of our aquatic plants are from other locations where Ca is low and Mg present in only trace amounts. 

GH is made of Ca and Mg. Approximately 7 ppm Ca is 1 dGH, 4.4 ppm Mg is 1 dGH. So if your GH is 5 dGH and Ca is 20 ppm, then there is 2 extra dGH. This extra GH must be Mg of about 9 ppm which is too much. You don't want it there. Where is it coming from?

There is no need to add any Mg because PPS-Pro takes care of it. 

Thank you
Edward


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## trong (Aug 8, 2006)

*Re: K2so4*

Ahha, there was a time about 5 months ago i was adding some Mg to the equillibrium during H2O changes because of suspected deficiencies and that was before i started using PPS-Pro. Since using pps-pro i'm not using seachem product just caso4. In fact, this is the kind of stuff that made me want to start pps-pro. I've noticed in things i've been reading that my ratio's of Ca/Mg were off and i've even posted on this matter i think? To my recollection, the responce posts were not to worry to much about that. And with the accuracy of the test kits these days i just dimissed it. The plants for the most part are doing great and the fish are healthy. The only thing a can think of where it's coming from must be the substrate, or bad test kits. Substrates seem to be able to have a life of there own storing and releasing stuff, right? I would think Mg added months ago would be gone by now,even if i wasn't having deficiencies back then. maybe it's time for me to dig into the science of substates, and buy new kits. I'll check the dates on kits. I'm going to check into the gypsum thing, thanks.


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## azfishguy (Jul 1, 2005)

*Re: K2so4*

I used gypsum from a garden store without a problem.


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## Left C (Jun 14, 2005)

*Re: K2so4*

Deleted.

Left C


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