Plant help

[fatboy8]

Started a 20 gallon planted tank a few months ago with water wisteria, Anubias, Italian Val, dwarf baby tears carpet, and hydrocotyle tripartia carpet. Tank is lighted by a fluval aquasky on the plant setting and filtered with fluval 50. I dose weekly with multiple products from fluval flourish, excel, dennerele vita max, and sera Florena.

My issue I’m having is I’m having great new growth on the wisteria but the lower leaves look whittled and turning brown. I saw a similar thread on here prior but can no longer find it. I believe it’s an iron deficiency but I wanted to be certain. I’m doing 50% W/C weekly.

 

[kno4te]

Suggest posting pics on what’s dying.

 

[fatboy8]

Suggest posting pics on what’s dying.

At work now will have to wait but the wisteria has new growth on the top half but the leaves closer to my substrate seem to be brown, whittled, and dying. I can’t see it being a lightening issue all other plants are doing fine.

 

[kno4te]

Might be getitng outcompeted with carbon/nitrates/micros/macros as it’s a fast grower.

 

[Coryloach]

There are two type of plant nutrients, mobile and immobile or in other words macro or micro nutrients.

Macro(mobile) nutrients are nitrogen (N), phosphorous (P), and potassium (K).

Micro(immobile) are most of the rest, such as iron(Fe), calcium(Ca), Boron(B) and many others.

Macro nutrients are required in big amounts by the plants. Micro nutrients are needed in micro quantities.

Now to your question,....macro nutrients show up as deficiencies on older leaves and if the deficiency is left unaddressed, the deficiency will eventually affect new growth, hence they're called mobile. Micro nutrients on another hand show up on new growth only and can not travel down to old leaves, hence called immobile.

The two other big plant essentials are CO2 and light, which can affect all parts of the plant. Plants can normally adapt to low CO2 levels but they will not grow sufficiently and may show deficiency signs, which are not set in stone but for the most part it will be some sort of visible physical damage. However, there is always some amount of CO2 in a tank, although rather low so the plant will live somehow.
In terms of light, there is a term called light compensation point for each species of plant which would determine the amount of light they need. If not enough light is provided, the plant will simply wither and eventually die.

If we ignore for now CO2 and light, your issue is one of the macro nutrients mentioned above, since old leaves are affected first...