I haven't decided whether the best answer to this problem is going to come from an apisto-phile or an aquatic gardener. Probably someone who is both, but maybe not, so I'm taking the liberty of double-posting. I live in Garden City Idaho, the closest thing Boise has to a suburb, and indeed it probably qualifies. We have less than 10,000 people, but draw our municiple water supply from nine different wells. The water leveles in the local aquifer go down in the summer and fall, and go back up in the winter and spring. The local geology is also quite diverse, and so as the water department switches around to the various wells, and the water in the aquifer rises and falls, water parameters vary. Sometimes I can use peat and other things to get fish to spawn, sometimes I can't. So I finally splurged and bought an entry-level de-ionizer. Now I have this really clean water, and can adjust the electrolyte levels to <60ppm GH and <90µs conductivity. But I want to provide a reasonable nutrient level for plants, also. I have the Homegrown Hydroponics "six-pack" and it seems I should be able to build my own electrolyte mix and PMDD formulas to meet the plants needs at the restrictive TDS limits necessary for the fish. For those not familiar with the sis-pack, it contains: 1)Calcium nitrate (CaNO3) 2)Potassium sulphate (K2SO4) 3)Potassium nitrate (KNO3) 4)Monopotassium phosphate (KH2PO4) 5)Magnesium sulphate (MgSO4) 6)Trace minerals mix, with Fe, Mg, Mn, etc. Percentages by weight are given with each one(in the really fine print), but one of the kids carried off my magnifying glass, so I'm going to have to wait until I find or replace it to mix the exact ratios of stuff. Can someone take a shot at mixing some or all of these into useable formulas, one for water re-constitution, and one for a fertilizer used every couple days? I will be making pH adjustments using HCl, unless something on this list will draw it down to 6.0-6.3 as part of the re-constitution thing. I wont be injecting CO2, and light levels will be fairly low. Thanks in advance, Bob Dixon Cichlid Trader List Administrator http://cichlidtrader.listbot.com ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!