re: reconstitution of, affects of RO water

---------- Forwarded message ----------
Date: Tue, 10 Dec 1996 11:27:16 -0500 (EST)
From: DIONIGI MALADORNO <MALADORD%A1%RNISD0 at mr_nut.roche.com>
Subject: reconstitution of, affects of RO water
To: AQUATIC PLANTS <Aquatic-Plants at ActWin_com>

NKLujan at aol_com wrote:

<<<<<Date: Mon, 9 Dec 1996 16:24:38 -0500
Subject: reconstitution of, affects of RO water>>>>>

I have been using RO water for the weekly 10% water changes in my 180 gal
discus tank since 3-4 months ago. My goal was to bring down conductivity
from ~250 microS/cm  (GH and KH at 3 deg, each) to ~80 in order to induce
spawning of my greens and browns, providing still the necessary nutrients
for the plants. I decided to use PMDD as a source of trace elements to
reconstitute the RO (I doubt that Kent really uses a critically better
formulation), and monitor KH and GH, adding minimal amounts of commercially
available "Malawi" salts to keep it in check. I add 3 ml PMDD to 13 gal. of
RO water with 0 conductivity, and occasional a 1/3 teaspoon of "African"
salts. I have chosen not to carefully control every change in the water
parameters (I am currently quite short in free time), but just use plants as
a trouble detector. 
The results are satisfactory: pH, alkalinity and hardness have stayed stable
with minimal corrections needed (GH went to 5 only one time I over corrected
it), conductivity seems now stabilized at 160 microS/cm (digested fish food
adds a lot to it, evidently), plants grow as well as before. I have not
achieved the low desired levels (probably I should increase the % of water
changes, but I first need to find a use for the additional reject water!),
and there is no sign of spawning yet (one fish has however assumed the
supposed pre-spawning color pattern of rear body bars) , but the plants are
fine and the water parameters are probably overall more suitable for South
American fish. Let me know if you need more details.