# dosing K using old Flourish K



## Nick (Jan 12, 2005)

Just started dosing a new tank set-up. Slightly confused as to how much K to add to my set-up (net volume 100 L, high light). Dosing would suggest ~2.5ml per 100 L, however if I input to the fertilator it returns a red number, i.e. less than 10 ppm equivalent dose, which appears to be the threshold for it going green-i'm assuming this indicates the minimum suggested dose. In order to get >10 ppm K added using F. Potassium suggests I should be using more like 22 ml, like 10 times the suggested dose!?! Am I missing something? I'm trying the whole range minus Excel and have pressurised CO2. Tank is in 1st week, and I use tapwater/RO to get desired GH/KH-am not using Equilibrium, so don't get K from that.

Thanks,
Nick


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## chiahead (Dec 18, 2004)

Hi Nick,
The recomended doses on the Flourish line of ferts is not tank specific. Its is used for a beginner dose and is usually too low for most tanks. I suggest if you can just test the water and go from there. I dose dry ferts except the flourish itself so I dont know if the fertilator is correct in that aspect(prob is). Also, most instr on the ferts say something like 1 or 2-3 times a week. Ultimately u either need to test or estimate your usage weekly. Hope this helps u out.


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## Nick (Jan 12, 2005)

Thanks-I guess the issue for me is that I can't test for K, and to be honest, I'm having trouble finding a good ballpark figure for what kind of levels/ppm I should aim for. In the absence of this, the main proxy for this is the amount going in during dosing. Today I just upped my dose 10 fold from ~2 ml to 20 ml, in line with what the fertilator suggests (i.e. goes green). This calcluates I'm adding ~10 ppm with a ~20 ml dose to my tank (net volume 100 L). Doing this 3 times a week would give 30 ppm on top of that present in the Flourish dose. How does that sound?

Thanks for your help,

Nick


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## chiahead (Dec 18, 2004)

Well, K is something u can have in excess so I would say it sounds fine. No probs I know of with excessive K, except extremely high causes a Ca uptake issue I hear. If u feel uncomfortable try dosing in the middle and watch them and see. Best bet is to watch the plants if they look good then dont change anything. maybe 10ml is safer esp if the tank is a newer setup as its needs a while to establish.


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## Nick (Jan 12, 2005)

ok, thanks for that. But I'm still a bit lost. Over a 6 day dosing period (and on the 7th, a water change) what kind of K levels sound reasonable to aim for , ppm-wise, assuming most of what I add is coming from Flourish K?

Thanks,
Nick


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## chiahead (Dec 18, 2004)

try to shoot for around 20-30 ppm of K. Thats what I have read anyways. Good luck!


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