Aquarium Plant leaves have dark spots on them.

[coodex]

Hello
Most of my Aquarium Plant leaves have dark spots on them.
I have a 100 ltr fresh water tank with 50W LED light system, DIY CO2 about 20-12 bubbles per minute. Eiem Pro 2 external filter. I had these spots on my ANUBIAS CONGENSIS and Anubias barteri plants when I used to have 2 x 18w T8 tubes. I use Excel FLourish when I had BBA and it cleared that, I still does Excel once a week and started to use E1 Started Kits - Dry Chemicals Plant food for the past 2 weeks but the dark spots have not cleared. Below is my water tested:
Cl2 0.8
PH 8.4
KH 20 d
GH 8 d
NO2 0
NO3 25
PO4 1.0 mg

Change 50% water every week. The fish are all ok and happy. Photos below:

 

[aqua_chem]

I'm not sure what "E1 Started Kits - Dry Chemicals Plant Food" is or what it entails. Could you elaborate on that?

That being said, you have two types of algae in your tank that I can see. First is BBA, which is the dark black fuzz/spots that is on your wisteria (and possibly other plants). This is usually caused by insufficient or inconsistent CO2 (a major possibility with DIY CO2 on a medium sized tank) and high light, which you likely have. The second is the circular green spots on the anubias and sagittaria. This is type of algae know as Green Spot Algae (GSA). GSA is usually found in high light, low CO2 environments as well, but can also point to low phosphate levels. It will commonly grow on slower growing plants such as the two I previously mentioned.

I would definitely look at upping your CO2 levels, and maybe consider going pressurized. If that is a decent LED setup, than you could potentially have a lot of life going into that tank.

 

[coodex]

"E1 Started Kits - Dry Chemicals Plant Food"

Thanks aqua_chem. Really I have all that wow!
I suspected my CO2 but was not 100% sure so I wanted an expert opinion.

"E1 Started Kits - Dry Chemicals Plant Food" consit of the follow dry salts.
Mix 1:
Potassium Nitrate KNO3
Potassium Phosphate KH2PO4
Magnesium Sulphate MgSO4

Mix 2:
Chelated Trace Elements 250g

You mix these with water and dose as recomended. Which I find very safe and after using these salts my fish seem to be more active. The algae I have was there before I used these salts.

 

[aqua_chem]

What's your dosing regimen like?

 

[coodex]

Dose as follows:
20ml mixture of Macro every other day, ie: Sun, Tues, Thur.
20ml mixture of Micro every other day, ie: Mon, Wed, Fri
Saturday rest and Sunday 50% water change.

 

[aqua_chem]

What's the ratios of the mixture? Without knowing what the composition is, it's impossible to know exactly how much you're dosing.

 

[coodex]

I am following the suppliers guidelines:

Macro Solution
Mix, Shake & Leave to Dissolve Overnight:
4tsp Potassium Nitrate
1tsp Potassium Phosphate
6tsp Magnesium Sulphate
500ml Water

Micro Solution
Mix, Shake & Leave to Dissolve Overnight:
1tsp Chelated Trace Elements
500ml Water