"linda mar" wrote in message
...
Dear experts..

snip

though far from an expert i can share my situation and see if there is
anything of relevance you (or someone else) can pull form it...

i have two main tanks, one 15 gal. tall and one standard 20 gal. both have
the same type of filtration systems (back of tank waterfall filters)
different substrates and different lighting. the 15 gal. has a sand
substrate while the 20 has large (1-1.5 cm) gravel sub. the 15 gal. receives
a great deal more natural light than the 20 gal. live plants do
exceptionally well in the 15, but not in the 20. the 15 has an Aqua-Glo 8 w.
12" bulb, the 20 has a Sylvania Enhanced 18" (no wattage). the water
parameters are the same in both tanks; 0 = ammonia, 0 = nitrite, 20ppm =
nitrate (odd to me considering one has plants and one doesnt)

the 15 gal. is almost always hazy while the 20 has always been crystal
clear.

i really dont know exactly what to infer from all this information, it could
be the substrate, the natural lighting, the artificial lighting, a
combination of all three or something else totally different. sorry i cant
be of any more help to you or offer any recomendations. /

best of luck!
tedd.