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GH/KH for dummies

Hi all,
I have been adding crushed/dust eggshell, so not sure if that can produce the same result.
Exactly the same, calcium carbonate (CaCO3).
Hanna Instruments HI-991301 Water Resistant pH, Conductivity and TDS Meter, High Range....£639.96.
That is a good meter, but it is a "High range" meter and ideally you want a "Low range" meter.
Thats one of the more pricey ones i found.
All lab. grade equipment is pretty pricey. There will be some cheaper ones that work OK.

cheers Darrel
 
Hi all,

Exactly the same, calcium carbonate (CaCO3).

That is a good meter, but it is a "High range" meter and ideally you want a "Low range" meter.

All lab. grade equipment is pretty pricey. There will be some cheaper ones that work OK.

cheers Darrel
My next question would be is it possible to add too much calcium?, and what are the chances of actually raising other parameters just by dosing with it when needed. Would you need to throw a ton of it in there to see a difference?
 
Hi all,
My next question would be is it possible to add too much calcium?
Not really, not for "hard water" plants, fish or shrimps. In <"natural situations"> a lot of water is <"fully saturated with calcium (Ca)"> from the dissolution of limestone (CaCO3). The derivation is a bit strange, but 7.14 mg / L (ppm) of Ca++ ions are "1 dGH".
1 dH is "One degree German" and defined as 10 milligrams of calcium oxide (CaO) per litre of water. This is equivalent to 17.86 milligrams of calcium carbonate per litre of water, or 17.86 ppm.
It is <"difficult to get more"> than about 125 mg/L (ppm) ~ 17 - 18 dGH calcium (Ca++) in solution, it just to do with the limits of <"calcium carbonate (CaCO3) solubility"> (about 315 mg / L).

As the water warms up that dGH (and dKH) value will fall, because warm water can hold less dissolved gases and it is the level of CO2 that controls the dissolution of CaCO3.

cheers Darrel
 
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I haven't had a chance to fully check its specification yet. I believe it's cheaper than the HI-98301.
Hi @Jaceree

The Hanna HI-98301 at £77.16 inc. VAT would be my preferred choice. But, the Hanna Primo Pocket TDS Tester would save you approximately £20 if budget was tight. Both can be calibrated. For me, the decider is the fact that the Primo Pocket TDS Tester is not submersible. However, the HI-98301 has a watertight battery compartment. So, there you have it.

Hope this is useful to you.

JPC
 
Hi @Jaceree

The Hanna HI-98301 at £77.16 inc. VAT would be my preferred choice. But, the Hanna Primo Pocket TDS Tester would save you approximately £20 if budget was tight. Both can be calibrated. For me, the decider is the fact that the Primo Pocket TDS Tester is not submersible. However, the HI-98301 has a watertight battery compartment. So, there you have it.

Hope this is useful to you.

JPC
Im going to look at them all before deciding. I try not to let the price dictate things usually, and consider how well something works first. I dont mind that the Primo pocket is not submersible.

Cheers.
 
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Hi @Jaceree

The Hanna HI-98301 at £77.16 inc. VAT would be my preferred choice.
That's the one I use and recommend. 👍 If I could only be allowed to use ONE measuring device in my tanks this would be it (I use the build in thermometer for water temperature as well). One slight annoyance with this model is that the LCD is not lit.

Cheers,
Michael
 
I inherited one of these from my brother who is too busy for hydroponics anymore. It seems to be a high range tds and ph meter. But it's working well for me at the moment since I just recently started co2 injection.
It doesn't have any way to connect to a raspberry pi or controller though unless I open it up and maybe take a reading straight from the lcd?
Anyone here ever tried that?
 

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I didn't read all the thread but there is one thing and one thing only that matters when breeding. Control and stability. Even if your tap water is perfect now you never know when and if it will start changing composition and you will at some point start to wonder what is going on and inevitably blame the water. So you would at least need a resin filter (if not RO) to maintain a constant level of hardness. This is paramount. I do not know a single pro breeder that does not control its water parameters in one way or the other. Hoping for tap or rainwater to be the same for eternity is looking for trouble.

Also, a word of warning. NEVER EVER raise or decrease the alkalinity of the water abruptly (specially with strong buffers) or you will find yourself with a graveyard. KH impacts the osmoregulatory functions of shrimps/fish fast due to sudden PH swings when adding the buffer. So KH needs to be adjusted in small increments in a matter of days/weeks.
 
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