High light to low light die back?

I have recently started a low tech 10 gallon at work and everything has been great with one exception. My Bacopa Carolinia which I took cuttings from my high tech 20 gallon has transparent leaves at the top (6 or 7 leaves on each plant). The rest of the plant appears healthy. Could this be symptom of die back as a result of switching from high light to low light?

The parameters:

20 gallon:
65 W Coralife PC 10 hours a day
Florabase
Pressurized CO2 on a solenoid with a timer
EI
50% water change a week

10 gallon:
30 watts from 2x Floraglo T8 (old canopies) - 15 watts for the full 9 hours, 30 watts for 4 hours
Inert gravel
Excel and trace twice a week
25% water change once every 2 weeks


All I have in the 10 gallon are some shrimps (Cherry and Japonica) and neon tetras. Other plants are doing fantastic, including java fern, java moss, Cabomba, and a small Crypt (not sure of species).

There is a piece of Malaysian ironwood in both tanks.

 

It's old tank that had been running for a couple of years with no plants except a couple of java ferns. So the substrate is very mature.

Should I dose lightly once a week? I took a test kit once and the nitrates read 10 ppm with phosphates about 2 ppm. Maybe I'll bring my test kits in tomorrow and test again. How much should I be dosing? Up to 10 ppm nitrates once a week? This is all new to me. My other low tech tank is a 125 gallon with big SA/CA cichlids and I have to change 20% of the water twice a week to keep nitrates @ 20 ppm.

 

Hmmm...looks like Vaugh is right. Just measured nitrates and phosphates. Nitrates = 5 ppm
phosphates = 1 ppm

So I am thinking I need to either increase the fish load or starting dosing some nitrates. Which is the preferred route? Can I increase fish load and keep this tank low maintenance?

 

I am normally dubious of over test kits, but I've run these kits (API) on my two other tanks and the levels seem indicative of the characteristics, so I would say that they are in the ballpark. I'll try dosing lightly to see if there is any improvement over a week.