All,

I've been doing a lot of research on how to keep plants and am hoping
someone would be kind enough to confirm or correct my conclusions and
answer some questions.

1. I understand that different plants need varying amounts of light
and some need a substrate while others will attach to rocks or
driftwood; also, different plants grow to different sizes. This
should all be researched and the proper plants/conditions
chosen/arranged. Makes sense.

Can anyone give a general listing of how many watts per gallon equate
to low, medium and high lighting?

There seems to be some difference in the light requirements with very
small tanks (those under 10g?) - is it that they need more watts per
gallon (because the wattage is so low) or that they don't need as many
watts because they're more shallow, or....?

2. Plants need carbon - this can come from CO2 (either what's in the
water or from an injection system) or from a liquid like Flourish
Excel. There are tests to measure CO2 in water, these or the
instructions on the bottle (plus observation) can be used to determine
amounts needed.

3. Plants need nutrients. From what I've read, it's possible they'll
get enough ammonia, nitrite, nitrate from the fish (but testing is
needed and if the nitrate is too low, it may be necessary to add
nitrate).

Phosphate may come from your water; depending on how much your water
has, you may need to add some. There are test kits for this.

Potassium - this probably needs to be added. There are some tests,
but they seem rare and pretty expensive. Probably best to follow the
directions for the fertilizer and/or use "nutrient deficiency"
symptoms to determine if this is needed.

"Trace nutrients" - it seems like the amount needed is based on the
results of iron tests or that you simply add based on the
recommendations on the bottle. (Is it safe to assume that calcium,
magnesium and sulfate tests aren't needed (for the average person)?).

Which of these (trace, nitrate, phosphate, potassium) can come from
the substrate (at least for plants planted in the substrate)? Do any
of these nutrients leach into the water for plants not planted in the
substrate?


Assuming the plants, lighting, carbon (dioxide), substrate and
fertilizers are all properly selected / applied, one should have a
healthy planted tank, no?

Thanks,

Liz