what are good numbers?

I'm a little confused by what you've got posted there... What kind of tests are you using?

You want ammonia and nitrite at 0ppm. Any reading at all other than 0 there, and you've got a cycling issue. Not a problem for plants, just for livestock.

Your pH is on the hard side. Not a huge issue, I'd just avoid plants and livestock that are very sensitive to hard water (not too many plants that are, Erios and Toninas would be 2 of the few exceptions).

yep as lauraleellbp noted the only two reading you need to really worry about are ammonia and nitrite, also if your using amazonia as your substrate which im assuming your not as your ph is oh the higher end, then you dont have to worry about ammonia reading as much as the substrate will leech it out.

Fish in the tank cycling?

Anything above 1 on ammonia and nitrite can be deadly to fish. A nitrate reading if 4 means you need to do a 75% water change.

Is this the tank with just snails (and soon to be shrimp? :angel?

Snails generally aren't *as* sensitive as fish to ammonia and nitrite, but I'd still try and get those levels down closer to 0.25ppm till the cycle finishes and they bottom out at 0ppm.

In a low light/low tech tank, there's no need to go over 20 ppm nitrates.

Ammonia, nitrite, and nitrates are all good sources of nitrogen for the plants. It's only the livestock that those can be toxic for, and it's only the first two that are highly toxic.

Once the tank has cycled, readings should be 0 ammonia and 0 nitrite. Nitrates at lower levels (generally speaking, under 20ppm) are fine. Ammonia and nitrites are damaging to any fauna, although snails survive better than fish. Plants can utilize ammonia, so a planted tank tends to be more stable than a non-planted tank.

EDITED TO ADD: Seeing as your tank is registering nitrates, it should already be cycled -- so the presence of ammonia and nitrites indicates a water quality problem. Might be in a mini-cycle from dead snails in the tank or meds or other additives impacting your filter bacteria. You might want to get a bottle of Seachem Stability to add good bacteria to the tank.

Sorry no octopus.

But do show us pics of the snails. Is this a snail breeding set-up?

so with a water change last night, my numbers this evening are :

pH 7.5
Ammonia 0.02
Nitrite 1ppm
Nitrate 10ppm

will adding Flourish or Flourish Excel increase these numbers?

I also have Flourish Iron and Flourish Trace, but I haven't added these yet

As long as you follow the recommended dosages with the Excel it shouldn't affect any of your parameters.

I don't think Comprehensive should, either... if it does, not by much (it's mostly micros and trace, not the "macros" N, P, or K. And ammonia, nitrite, and nitrate are all N).

Under your current low lighting, you may not need to dose Trace. Chances are pretty good the plants can get the trace nutrients they need just from the snail waste and/or tap water. (If you step up your lighting or incorporate some fast-growing-nutrient-hog stem plants, then you might need Trace.)

You might need to dose P and K... or possibly not.

Really, you just need to learn to "read" your plants. You'll start seeing discolorations, holes in leaves, leaf twisting/warping if you get nutrient deficiencies. Nice thing is under low light conditions, things go so much more slowly. You should have time to notice and do some trial and error to figure it out if anything starts to go wrong.

thanks LauraLee!