On Thu, 17 Nov 2005 20:30:11 -0700, Liz McGuire wrote:

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

That's a difficult estimate to make. My 2.5G has 13W on it (5+ WPG) but
is considered medium. My 55 has 180W on it (3+ WPG) and is also medium to
medium high depending on who you ask.

How big of a tank are you working with? What a lot of people don't mention
is that you should aim for medium at first- learning with high light can
be frustrating.

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.

Assuming you don't use peat or blackwater mixes, there's a better way.
Measure pH and KH and look it up he

http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

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).

They probably will get enough in medium light with a decent fishload.

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.

Fish food is also high in phosphate.

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.

Iron before pottassium, definitely.

"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)?).

Calcium magnesium and sulphate are present in tapwater. If your GH is
medium range out of the tap you will be fine.

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

There's one other thing to mention: water changes. Doing them frequently
(I do 25-30% weekly) helps keep your water fresh. It removes DOCs
(dissolved organic compounds), replenishes KH and GH, and keeps your water
from getting buildups of fertilizers or other stuff. Plus it's a good
excuse to remove dead plant matter and perform other tasks. In a planted
tank you only want to vac the top 1/2" of substrate. Anything deeper can
become plant fertilizer.

Go visit fishgeek.net- it's a very good resource.

~Empty