You don't need a TDS meter but it's handy sometimes. You definitely need a phosphate testing kit.
You might not believe me but the snails don't need to be fed. They feed on microalgae and need very little. I don't think feeding them that small amount of pellets is a problem though unless they are decaying on the sand bed and not getting eaten.
You can get a phosphate adsorbing pad, or some GFO to throw in a mesh bag with the carbon. Carbon doesn't rid the water of phosphates or nitrates.
Are you on a water change routine yet? You should pick a day of the week and do a pwc on that day every week.
You might not believe me but the snails don't need to be fed. They feed on microalgae and need very little. I don't think feeding them that small amount of pellets is a problem though unless they are decaying on the sand bed and not getting eaten.
You can get a phosphate adsorbing pad, or some GFO to throw in a mesh bag with the carbon. Carbon doesn't rid the water of phosphates or nitrates.
Are you on a water change routine yet? You should pick a day of the week and do a pwc on that day every week.