No blackwater extract or anything like that. I did try some crushed coral to raise KH. I'm not keeping the water lower than 6.8. It's doing that on it's on. I wish it would stay at 6.8.Ted, I started cycling about 7 weeks ago. Added 3ppm ammonia. 3 weeks later, no change, still 3ppm ammonia, no nitrite, no nitrate. I started a thread on another forum and learned about PH crash. Checked PH for the first time and discovered a PH of 6.0 ( bottom range of my test kit ) or lower. Changed 50% of water, to get the PH back up, as I was told that low PH would hinder or stop the cycle. I added more ammonia with water change. The water change helped. I started getting some nitrites. I've been doing 50% changes twice a week for about a month now. My take is that either low PH or possibly fluctuating PH is my problem, but the PH stayed constant for the first 3 weeks. BTW I have been adding squeezings from established filters, but I fear that's not much help. I don't think my established tanks have much bacteria either because of low PH. I've bought 3 boxes of plants. I'm installing lights over all my tanks and will see if that will help. I am determined to make this thing work. Thanks again.