What am i deficient in? Stem plant old leaves not doing well.

[Nick Norman]

New growth is healthy and reasonable quick, but older leaves look scruffy and unhealthy just as quick. What do they need to stay healthy? the Limnophilla Heterophilla is affected the most. I have started to dose Potassium Sulphate, do i need to be adding phosphate or something else? Any advice appreciated.

My Tank:

5 months old
110L
Medium fish stock
Aqua Ray LED Aqua Bar x2 (think this is low to medium light)
Liquid carbon (daily)
Easy Life Profito (Daily)
Just started dosing Potassium Sulphate (only one week)
Tap water has high Nitrate
30% PWC weekly

Plants

Rotala Rotundifolia
Limnophila Heterophylla
Bacopa Caroliniana
Crypts
Java Fern Trident
S. Repens
Anubias Nana
Hygrophila Salicifolia

 

[Julian]

Light.

 

[Nick Norman]

I have wondered if i have enough light for some of the stem plants., I haven't been able to find any PAR or Lumen info on the TMC AquaBar. I was hoping they where medium light with two of them. Are the light demands of Limnophila Heterophylla high? The Rotala Rotundifolia suffers as well.

 

[EdwinK]

If you have Aquasoil Amazonia which tends to absorb phosphates try upping it to 1 ppm per day. On the presumption that your tap water has high nitrates and you are dosing potassium you are missing phosphates because it's a motile nutrient, and your old leaves are suffering.

 

[Nick Norman]

Yeah i have Amazonia Aquasoil. should I test for phosphate first then add what is needed to take it to 1ppm? are the test kits accurate? or just dose 1ppm each day?

I will try phosphate first, if i don't get any results using ferts maybe I will up the light, or change plants. All of the plant was healthy for the first month and grew fast, thought maybe it was getting nutrients from the soil which are now used up, or maybe had reserves in the plant?

 

[tim]

Profito contains no nitrogen or phosphate source, could be either of these ?

 

[Nick Norman]

My tap water contains about 30 ppm of nitrate, according to my API test kit. I'm assuming this supplies enough nitrogen. Will start adding phosphate. I have read that to much phosphate can cause algae problems so I suppose I should test for it first?

 

[EdwinK]

If you have a test kit for phosphates then do it. Otherwise just start adding 1 ppm and observe for a week how plants react. Change nothing else to see if that was the case.