Winged's Tanks

I decided to replace most of the gravel in my 20 gallon planted tank to Flourite. I say most because I couldn't afford to get two bags. I wasn't sure if I would like how it looked, and the main reason I got it was because I didn't feel lie driving across town to get Eco-complete. But, after I started rinsing the stuff, all I could think was how awesome it would look.

Before the rescape and gravel change:



The bag says rinsing isn't necessary, that any cloudyness, which should be minimal, would clear within twelve hours. I decided to rinse it anyway because I was also putting new plants in and I wanted to see how they looked. I started rinsing and the first time through the water was almost black! I rinsed the stuff for about ten minutes, and the water was still coming out pretty brown. I gave up and decided to put it in my tank. I took most of the water out and all the fish and plants. I then proceeded to pull out some of the gravel and add the Flourite in its place. Once I did that, I started adding water and then plants. The water was nearly opaque. I planted what plants I could, but it was just so difficult to see. Here's what the tank looked like after almost five hours of work:

And the next morning:

The tank still looks like that, though the water is clear now. I need to do some real planting and planning. I have more plants waiting to go in the tank. A couple days after making the switch to Flourite, I started losing my ember tetras. I lost four or five in one day, and one on a couple other days. I am down to two from what was nine. I don't know what's killing them. The two remaining are in a hospital tank, not being treated yet. They are receiving daily water changes, and are being observed to see if I can find any real symptoms. The other seven never showed any, except paled colour, which I attributed to the stress from when I was messing with the tank, and not schooling with the others, which they didn't start to do until about twenty-four hours prior to death. It's been suggested that I treat them with Maracyn and Maracyn 2, but I am hesitant to use meds.

Also, since this is the first time for a post about this tank, I'd thought I'd share some of the specs:
-20 gallon high, measuring 24" L x 13" W x 17" H
-Lighting: 2 compact fluorescent bulbs, totalling in 40 watts
-Ferts: none
-Filter: Penguin 200
-Heat: Marineland Visi-therm Stealth 100 watts
-Plants: microsword (Lilaeopsis brasiliensis), Alternanthera reineckii, java fern (Microsorum pteropus), dwarf hairgrass (Eleocharis acicularis), jungle val (Vallisneria americana), dwarf sag (Sagittaria subulata), stargrass (Heteranthera zosterifolia)
-Fish: sparkling gourami (Trichopsis pumila), 8 pygmy cory cats (corydoras pygmaeus), 2 female guppies (Poecilia reticulata, temporarily)

We currently have 8 fish tanks, two saltwater, five freshwater, and one brackish water.

Our current setups:
55 gallon reef tank
8 gallon nano reef tank
45 gallon tropical community
20 gallon tropical community
5 gallon betta
5 gallon hex guppy
2.5 gallon betta
10 gallon mudskipper (soon to be a 29 gallon)