So I finally got around to getting an a API freshwater test kit. Old school, I had multiple tanks in the old days long before cycling was an issue. When I got back in, I used a Seachem Ammonia Alert monitor for ammonia and when I saw a spike, did a partial water change - it worked well.
Anyway, when I tested my tank water, I was surprised to see very high nitrates of 60~ppm (ammonia and nitrites were zero). I was surprised because I had just done my 50% weekly water change (just like every week) two days before. Digging deeper, I realize my (country well) water tests at 60~ppm right out of the tap. I suspect the result of a 95 acre fertilized farm land across the road!
I already have an AC70 filter dedicated to Matrix and two 100ml Purigen pouches in the other as well as recently added several bunches of (Ancharis) floating plants. (I don't have sufficient lighting to deal with rooted plants in this tank). I use Prime for water changes, but Prime only detoxes nitrates for about 48 hrs.
I tore the tank down, cleaned the substrate (went back from a gravel/sand mix to a thin layer of gravel), went back up with a mix of store bought water and my water, but the dilution was no where near enough. I still have over 40ppm nitrates.
I guess I'm going to have to get a tap water filter (API makes one) and/or a tank filter to [better] deal with nitrates. I can't afford an Aquaripure right now, but have an idea on a DIY alternative using Matrix and De*Nitrate.