Help..my plants look awful

[Ruby.doo1]

Hi, I'm new to this forum and wonder if someone could give me a bit of guidance. I have been keeping fish for over 20 years ,but this is my first planted tank ( my other tanks are 300 litres and 120 litres hardscape only).
This tank has been running for approx 5 years, I had only the floaters, java fern, anubias and driftwood in it with some water wisteria that I have taken out now ( it went crazy) prior to about a month ago.
I have planted some hygrophila polysperma in the last 4 weeks..looked good at first but now has lost all it's bottom leaves and even new growth is looking sad.
60 litre tank although it's only got about 50 litres of water in it:
Filtration is a U1 only
Temp at 22 degrees as I have dwarf emerald rasboras in there x 6 as well as espeis ( who have been fine at this temp) x 4.
Normal gravel only as I'm not keeping root plants. Dosing with 1 ml easy carbo just before lights on in the morning. Lights are on for 7 hours however dimmed at approx 50 % for 2 of these hours.
Dosing with Tnc complete weekly.
Never had a problem with any of the other low tech plants , just the polysperma. Changed to Tnc about 2 weeks ago as I was only dosing easy profito which doesnt contain nitrogen and thought it may be that...any ideas please as I don't want to purchase any more dwarf emerald until I can get on top of the planting situation.
Thanks. I've attached some photos.

 

[tam]

Welcome to the forum How are your floating plants? Could we have a photo? They are a really good way to judge nutrient deficiencies in your tank.

 

[Ruby.doo1]

Hi..thanks for getting back..I'm not at home right now but I'll take a photo once I'm back in about 1/2 hour. My floating plants seem fine- I occasionally get a yellow leaf in my bigger floaters but I think that's because they get wet as they get pushed around a bit. I have to scoop some out every couple of weeks as the duckweed?? Multiplies like mad. My ph is 7.5. 0 nitrite and 0 ammonia. My tank is only lightly stocked with small fish and I must admit I have about 20 assassins in there. I have moved them around my tanks as I have in total about 60. They eat fish food and I feed them hikari carnivore pellets in a shrimp dish every so often as I don't have any snails for them anymore.

 

[Ruby.doo1]

 

[dw1305]

Hi all,

How are your floating plants? Could we have a photo? They are a really good way to judge nutrient deficiencies in your tank.

My floating plants seem fine- I occasionally get a yellow leaf in my bigger floaters but I think that's because they get wet as they get pushed around a bit. I have to scoop some out every couple of weeks as the duckweed?? Multiplies like mad.

I've attached some photos.

Perfect, that <"looks like a light issue">.

Lights are on for 7 hours however dimmed at approx 50 % for 2 of these hours.

Try the light for another hour (eight in total) at 100%.

cheers Darrel

 

[Ruby.doo1]

Hi Darrel.. ah ok, so 100% for the whole 8 hours?... Ill try that and hopefully that will help them..I was just being a bit over cautious I guess. I hope this helps as I know my dwarf emeralds should be in a bigger number but wasn't happy to purchase anymore until I had this a bit more under control for fear of killing them off!! Thank you.