Hi
@D.Bezinski Black Beard Algae (BBA)... Looks like a classic CO2 issue to me. Is this DIY CO2 like a yeast based system? Those are prone to inconsistent delivery causing fluctuating CO2 levels.... a standing invitation to BBA. Your best bet is to dial down the light intensity (not hours/photoperiod), increase your water change frequency and/or % amount and improve your flow/circulation. WRT water parameters, the things that sticks out is the low PO4 levels - I would bump that to 4-5 ppm. I would supplement your Tropica Premium with some Phosphate (which your not getting with Premium) and possibly Potassium (which is too low with Premium) and Mg if your in the parts of the UK where there are very little Mg in the water. To error on the safe side with NO3 you could supplement with Nitrogen (your also not getting any NO3 with Tropica Premium), say 12ppm/wk. which will bring you into the 15-40ppm range based on the tap reports 3-28ppm. range.
You can also spot treat the Anubias with Carbo, brushing it onto the leaves and let it dry for a couple of minutes - just make sure you don't get carbo into the rhizome or roots as that will kill the plant. Dosing Carbo to combat BBA seems to be a hit and miss... You have to go all-in on all the above. BBA is
very persistent, so it may take a while before seeing improvements.
As for the hard water; personally I would aim for softer water for the livestock, not the plants (I don't see any plants there that require soft water), but its not essential.
Welcome to UKAPS
🙂
Cheers,
Michael