# Relationship Between KH and Plant Growth



## Homer_Simpson (Apr 2, 2007)

My KH Test Kits indicates that a KH between 50 to 120 ppm is considered "ideal" carbonate hardness re: PH stability and plant growth. So, do I have a problem if my KH is 20 ppm. And if so, what is best way to increase KH(??Baking Soda???) Is it just a coincidence that the snail ridden tanks have a high KH or do the snails/shells serve to raise KH?

I currently have 4 tanks and this is what the testing shows.

My Experimental Anti-Algae Tank: 20 ppm KH, PH is 7.0 No c02 or excel(PPS-Pro Fertilization) No algae yet, but has been running only since July 22 2007 30% weekly water change. So far, plants are growing like crazy.

Another 10 gallon with DIY c02 and Excel(PPS-Pro Fertilization) that is over-run with snails and brown dust algae that I can only remove by scraping with a credit card. Carbonate hardness is within optimal range of 80 with PH of 6.5. 50% weekly water change

My 40 Gallon with DIY C02 injection and Excel(PPS-Pro Fertilization). Overun with Black Beard Algae and hair algae(PPS-PRo Fertilization). KH is 20 PPM and PH is 6.5. 30% weekly water change

My 5 gallon Hex. DIY C02 and Excel. Also over-run with brown dust algae and green dot algae. Fertilization is Kent Pro Plant and Iron 1/8 tsp 3x/week with 30% weekly water changes. 

My 2.5 gallon Hex. DIY C02 and Excel. Fertilization is with Seachem Trace, Iron, Nitrogen, Potassium as per Seachem dosing schedule for 2.5 gallon. Persistent algae on tank walls inside, light green, but easily removed with sponge. 5% weekly water change as per Seachem recommendation.

Thanks.


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## ed seeley (Dec 1, 2006)

Homer_Simpson said:


> My KH Test Kits indicates that a KH between 50 to 120 ppm is considered "ideal" carbonate hardness re: PH stability and plant growth. So, do I have a problem if my KH is 20 ppm. And if so, what is best way to increase KH(??Baking Soda???) Is it just a coincidence that the snail ridden tanks have a high KH or do the snails/shells serve to raise KH.


I use RO water and used to remineralise it with RO Right, thinking I was adding GH and KH, but it turned out it doesn't add any KH so I had water with 0dKH and you know what all my tanks are doing very well on it. As it works so well I haven't changed and won't.
I keep softwater species and they love it. Rotala wallichi and Cabomba grow like weeds, among others. I use pressurised CO2, DIY CO2 and no CO2 on different tanks and it seems to make no difference to the fish or plants. No problems with pH stabiblity that I've seen either and I've been testing more regularly recently. No snails either - I've even killed apple snails which is supposed to be impossible!


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## Homer_Simpson (Apr 2, 2007)

O.k. thanks ed seeley. I was hoping to work with my existing water rather than switching to RO water. But I guess I may have to seriously consider this down the line as my tap water also is extremely high in phosphates.


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