quick note a relay/printer port control card 29-70 bucks . 8 buck relays to ??? control 1 amp to 200 (200-- 100 mh or hps) Look for relayrunner to try it for free . Now ph ppm ,co2 will need to be done the old fashion way, once a day. Have used this system for a dacade one failure ,,, computer battery. Its on computer time so power failures are no porblem. Spend 4 bucks a year for a computer battery. Anything that can run windows 95 , a screem fast 8mhz machine. Im runing a 20mhz (never know when I'll need the .0002 ms extra speed) I use a dataq 48 buck 4 channel recorder. 16 channel is better if you want to bonkers with data See my gallery Old sanclem or sanclem