Plants Going Brown

[thomtom]

Hi All,
 
I have had plants in the tank for about a month and they are growing upwards at a rate that I am happy with but the lower leaves are starting to get thin and brown. It almost looks like they are dirty, it doesn't rub off under my fingers though.The top leaves are a much lighter green to the older leaves and new leaves are appearing all the time at the top of the plant.
 
I have a 96L tank with an 18W T5 bulb, (it is a Jewel Rekord 96) I also have a small 9 LED Interpet strip, mainly to make the tank look nice . The lights are on for 6 hours a day but the tank is also quite close to a large window so the tank is also getting a fair bit of natural light throughout the day. I am adding around 3ml of Tetra PlantaMin every other day and also 5ml per 10L on water changes. I am not injecting C02 but I am starting to wonder if this would be beneficial.
 
There are no signs of algae in the rest of the tank and I change roughly 20% water each week.
 
Water Parameters:
 
PH. 7.5
KH: 3
Nitrite: 0
Ammonia: 0
 
Here is a picture of what the leaves are looking like, apologies for the poor quality. (the plants look worse in the flesh):
 

 

 

[ReddSamurai]

looks like algae to me, maybe too much natural light is going into the tank?

 

[snazy]

Yes, it's algae. It seems like too much light too. I'd cut the artificial lighting hours to a minimum first, just for viewing purposes and see how it goes. It would happen on the lower leaves as they've spent longer time in the tank, enough to grow algae on them.
If they are melting though, then the flow isn't reaching the lower levels to distribute nutritients.

 

[thomtom]

I will drop to 2 hours of lighting and see if that helps, Will I need to trim the algae leaves or will it die off with less lighting? Would C02 injection help to reduce the algae?
 
I think ill buy a solid coloured background and run it around the back and side closest to the windows to try and cut out a bit more of the natural light.
 
Thanks for your help. ps, snazzy I really like the look of the tank in your sig.

 

[snazy]

Thanks Tomthom.
It's best if you trim all affected leaves and parts of the plants. Even replant the tops only, then drastically decrease the light.
You can plant a few more plants too and it's a good idea to get floating plants for a setup like this. They help a lot with algae, taking up excess nutritients and blocking unnecessary light