Hi guys, I,ve been reading posts here for awhile but I thought I would introduce myself and ask a question or two. I have a 170lt (35 gal) heavily planted tank with PH7 and KH 2.2dg or 40ppm. I,m supplementing CO2 with a carbo plus unit and add seachem fertilizer. Light is 1x36watt gro-lux, 1x36watt 10000k tropical aquastar and a 5000k 140watt compact fluro. Is the KH too low for good plant growth. Ammonia, nitrite and nitrates are all O. Nitrates go up slightly with a heavy fish feed. (45 inches of fish). I also have a question about eheim CO2 monitors. Mine went to yellow which is supposed to indicate too much CO2 but when I did a PH, KH chart comparison the chart said I only had 7 ppm of CO2. So which one is wrong, the eheim monitor or the chart. Thanks.