I have a 46-gallon bow front freshwater aquarium and have a few
questions about lighting and replacing water using a tap water filter.
Fist, I seem to have a problem growing certain plants, especially ones
in the foreground. I have a coralife 192-watt compact fluorescent light,
6700k. Which should be sufficient for any high light plant, right?

1/2 this lighting will grow _any_ plant I know of.
The issue is too much lighting likely. But we can figure out what you
need to do about it.

purchased the stands for the light housing but I'm not sure it would
help to offset the light 2" off the top or not? The tank is bowed, so
maybe that is why I have a problem growing plants in the foreground.

This has not been a problem for several large bow fronts I've set up
over the years, they had massive fields of Gloss that did fine with
1/3-1/2 this lighting.

I
have two one-gallon glass jugs for DIY Co2 as well, with the tubing
routing through the intake of my canister filter. One of the plants I am
talking about is; Micro sword-lilaeopsis (looks like grass) I have
standard gravel and some laterite mixed in as well. The grass just seems
to grow algae and die off. My water parameters are, PH 6.5, ammonia is
good, nitrite is good, and water hardness is low.

Well at high light you place more demand on the CO2, DIY CO2 + over 4
watts gal of lighting is a BAD combination, you should have gotten the
Gas tank CO2 first,before the high lighting.
CO2 is your weak link here and you need to either keep up on the DIY
and work at getting it to maintain enough CO2, 20-30ppm the entire
time the lights are or use gas tank CO2.

Second, the way I filter my water is with a "tap water filter" by
aquarium pharmaceuticals. I was wondering if there was a cheaper
alternative to filter tap water other than purchasing a replacement
filter every month.

Sure, use tap water. The tap water is fine for plants, you migfht want
soft water for only certain species of fish, but what is wrong with
the tap water that makes you use tap water filters or want to use RO?

I'll tell you this, you are not helping the plants by doing this, CO2
is what they are concerned about, soft vs hard water makes no
difference in plant growth. This is myth that plants prefer soft
water.

I have been looking at the RO filters, like the
deluxe maxxima 35 HI-S by Kent Marine. Would something like that save
money later on down the road? Or should I keep on buying the tap water
filter replacements? My tap water out of the faucet is very hard and
high in PH.

But you use CO2, it makes no difference as far as the plants are
concerned.
I've got pictures in TFH with very hard tap water plant tanks, KH 10 ,
GH 24 etc.
Plants grow fine if you add enough GH/KH roughly 3, but I do not know
of any upper limits, some folks do fine at 20KH and I know from years
of growing at 10KH, 24GH, high GH seems to help more than anything,
not harm plants in any way.

It's all about the CO2, if you want to save $, buy an CO2 system, you
do not need a RO for helping plants grow better. I've only seen a
couple of cases where it was well water with high salt content and
once with high copper in their pipes/supply etc. But barring these
very rare exceptions, it's a myth soft water helps plant growth.

Now your fish might prefer softer water, but the plant could care
less.
I've had and used both hard and soft water with some 250+ species of
aquatic plants. Buy the Gas CO2 or keep up on the DIY. Use plain tap
water, adjust the pH using only CO2 gas to get a CO2 level of 20-30ppm
during the entire light cycle.
see the pH/KH/CO2 table to determine the CO2 by measuring the KH
first, then seeing what pH you'll need to get a CO2 level of 20-30ppm.
Use only CO2 gas to change the pH, this is what the plants want, not
soft water/low pH etc.
Regards,
Tom Barr




Any help is appreciated!!!



Thanks,

James