Getting back into aquaria after many years. Never had test equipment as a kid, so new to me. Have a 10 gallon tank in which I simply can't get the nitrates down. Small and large water changes with filtered water, suctioning bottom, filter changes, Ammo-lock (last resort) and still can win. Lost a Zebra today, and looking at moving the fist (two cats, one Neon, one Zebra) to a 40 gallon tank with good water quality. Then start over with 10 gallon. Trying to bring temp up a bit in 10 gallon tank before transfer (3 degree difference). Is there another alternative I haven't considered for the 10 gallon tank? Or is starting over best after transfer. Any other water parameters I should worry about before transfer? Yes, the fish are compatible. Thanks for any advice!