Floating Salvinia Dying

[Darkfung]

Hi,

I bought 25 Salvinia Auriculata plants - whilst they've sprouted offshoots rapidly the big plants seem to be turning brown and dying - my 65 litre tank has the lights on for about 7 hours per day (tank has also been going for over 6 months and fish are now quite happy - no chemicals added to water etc. correct PH, nitrate, nitrite for livebearers) ...... I'm new to plants so is the light on for too short a time? is the plant too close to the light bulb maybe ???
As always any advice is welcome -

 

[RadaR]

They can melt after being introduced for the first time to the tank. They soon regain themselves though and recover.
Light isn't an issue because at the surface they are bound to get enough. Also, CO2 can be ruled out because salvinia will get that from the atmosphere. It must be nutrients then. Nitrogen, Phosphrous, Potassium or trace elements.

correct PH, nitrate, nitrite for livebearers

I'm guessing that by that you mean the nitrate is close to "0"?

When and how much is the water changed?

 

[Darkfung]

They can melt after being introduced for the first time to the tank. They soon regain themselves though and recover.
Light isn't an issue because at the surface they are bound to get enough. Also, CO2 can be ruled out because salvinia will get that from the atmosphere. It must be nutrients then. Nitrogen, Phosphrous, Potassium or trace elements.

correct PH, nitrate, nitrite for livebearers

I'm guessing that by that you mean the nitrate is close to "0"?

When and how much is the water changed?

On average I'd guess I change out about 6 litres a week ...... probably round about 10% of the water ......... I'm planning to buy some plant food supplement, see if that helps ..

I tested the water
Nitrate = 5
P.H. = 7.3
Ammonia = 0
Nitrite = 0
Fish are guppies, mollies, swordtails, rainbow fish amd harlequins.

 

[tom_os]

some floating plants can shrink if they dont get fertilizers

i dont know if that applys to your though