so do you think you have black hair algea ?
ist of all you need to clean any algea fron the tank/plants
if you are goig to opt for a single light period.
baby steps are req
I would go for a 6.5 hr lighting period, then each week increase by 15 mins, till you get to your 8hr period,
dose the liquid ferts & Carbon, 30 mins before lights on and dont have any airstones running or anything else which breaks the surface of the water, during the photoperiod time, as this would make the carbon usless,
using Neutro C02 its 250ltr per 5 ml so work on the basis of, 1ml per 50 ltrs so rather than 3ml you could get away with 4ml being 180ltr tank, thats what i dosed my 180ltr
but watch the fish in the tank very carefully, if you do ever overdose just put your filter outlet above the water line to get the oxygen back into the tank, and a water change.
(i speak from experiance i dosed 12ml one day) lucky i didnt loose any fish.
the reason i advise to reduce the time then increase slowly, plants can get grumpy when they get used to a certain light timings, and a massive sudden change can some times shock them, and some times refuse to grow.
so some suggest when starting a planted tank start with a 7hr photo period then as the plants grow, increase it slowly
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Knowledge is knowing that a tomato is a fruit, wisdom is knowing not to put it in a fruit salad!
I dont keep fish i keep water the fish are only there for decoration