60g, unplanted tank. It's a long story but I discovered that my tap (country well) water was very high in nitrates 60ppm+! Even though I was doing proper housekeeping with gravel siphoning, 50% weekly water changes and filter maintenance, I was having peculiar fish losses. I decided to make a denitrator filter. It uses a kitchen type lock top canister, a combination of Seachem Matrix and Seachem De*Nitrate and a Tom aqua lifter pump. See Photo log. I'm in the process now of cycling the filter/tank using Seachem Stability. As you can see from the water test photo, Nitrates are very high. I will report on progress.