Hello all. I'm somewhere in between a newbie and experienced. I've had small tanks previously and worked at pet stores where I've learned a lot from people who are advanced. I recently set up a 29 gallon, and have a HOB filter with assorted media. I have Modano driftwood, Caribsea fluorite substrate, tank is kept at 80F, and I have a small assortment of live plants. Wisteria, anacharis, Java fern, dwarf hair grass. I have a few cherry barbs, harlequin rasboras, a dwarf gourami, corydora, ghost shrimp, and some platies. I use Seachem Flourish and Flourish excel. I do frequent water changes because the tannins from the driftwood. I remove about 13 gallons every 3 or 4 days. Have a 32 gallon trashcan I store dechlorinated water in, with power head and heater. My source water is very hard, but same parameters as store I got the fish from. (I work there so I'm sure of this.) I believe the chloramines in the tap water are very high so I try to use extra Seachem Prime. I have lost a few fish. One rasbora, which was very tiny. Netted it and tested my water and did a water change. I didn't think anything of it. A few days later I added 2 Julii corydoras, and then lost one. Thought maybe it was just sensitive to the environment change. Tested water, water change. Then I got home last night and had lost an albino cory and one of my 2 dwarf gourami. I believe my water is fine, honestly no matter what water I test with my API master kit I feel like I see between 0 and 0.25 ppm. I even ordered strip tests to confirm if I actually have ammonia or if I'm having difficulty reading my current kit. But no nitrites and very low nitrates, between 5-10 ppm. Fish appear normal and healthy until they're not. Help?