depending on your space, try bending the older ones.

perfect your germination methods (90% is goal).

flush with distilled water once a month if persist in using municipal water, and use a final flush justb4 harvest.

a good RO purifier will pay for itself in the long haul. just because it is capable of doing 100 gallons a day, doesn't mean you have to run that much. hook one up to your sink, and drink it and wash face in it, awesome bonus!