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Ro g/h k/h

1115 Views 5 Replies 4 Participants Last post by  livingword26
I've been looking at buying an RO system. I have been trying to decide what I need to use to reconstitute the water. I am not interested in using my tap water in a mixture. I have been looking at Seachem Equilibrium, and GLA G/H booster, which are about the same thing I beleive. Neither of these products claim to do anything for K/H. Do I need to add something else to reconstitute the water? What is ideal g/h, k/h? I will be dosing KNO3, KH2PO4, and probably Flourish for micro's. Low/Medium light, and pressurized co2.
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my take on setting RO

The grind on the minerals is finer with the GLA product so it seems to mix better for me.
I've used three 'ready blends' and GLA gets my repeat orders.

CaCO3 doesn't mix very well in my experience using it. I use baking soda because it has great solubility, low cost, availability and consistent results. No issues with it precipitating out of solution either. The sodium content of baking soda isn't a high enough concentration at the level I dose to effect flora or fauna. Dosed at water changes to test out as 2dKH is enough to maintain stable PH values in the 7.0 - 7.4 range without CO2 and enough to prevent a pH crash using gas. I've only once seen tested values drop after setting parameters and that was after long term neglect on a trimmings tank.

To increase KH (using leveled teaspoons)
1/8 TSP : 6.6 gallons = 1dKH
1/4 TSP : 13.2 gallons = 1dKH
1/2 TSP : 26.4 gallons = 1dKH

I keep softwater parameters in the 3-5dGH range and always mix for 2dKH.
TDS stays in the lower range and I like the results.

Potassium carbonate or calcium based are our 2 best choices looking for a buffer. BS is the cheapest, has great solubility and is readily available.

In the past I have added limestone (Texas holy rock) to my hardscape and didn't like how much my water increased in buffer over a weeks time (Rising everyday). Crushed coral would do the same thing so does cuttlebone. With the BS I mix to a desired value and there it remains.

I prefer static changes I can control so I've stayed with the BS for KH.
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IME there is no need to adjust the KH, i use 100% RO and no Kh at all, only dose GH booster and my ferts. never seen a fish suffer from low KH.
When changing a tank form tap water(350 ppm tsd, 10 gh, 6 kh), to an ro/tap water mixture, of 33% tap water / 66% ro water, The expected outcome would be 116ppm tsd, 3.3gh, and 2kh. How much time should I take converting to this mixture, with weekly water changes, to keep from shocking my critters and plants?
I would figure out the math so that the TDS is lowered by no more than 10% at any one time. You could do 2 such changes per week. So...
Now: TDS 350
WC, new TDS 315
...and so on.
Might take a month or more to drop it as much as you want, and that is OK, the fish need time to adjust.
This is a very conservative method, but I have used it with some pretty delicate fish and they were fine.
Thanks Diana.
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