And the odd thing
is plants sucking up so much CO2 that even I increased the CO2
injection a lot, pH still stand at roughly 6.7 - 6.8. And the good
news is that the thread algae's almost completely disappeared.

This often happens and one reason why I suggest 20-30ppm rather than
old standard of 15ppm.

However, I have otherr worries... its hard to keep the growth rate
like this, i.e. a lot of work. But I am afraid of that if I slowly
reduce the growth rate, algae might just reappear, but that's another
story.
Anyway, it works.
Cheers
Kenneth

That's easy enough, switch to slower growers like Cryopts for a
certain % of the tank, or driftwood covered with those slower growing
plants whuile still retaining a few fast growers.

Also, less light = less growth when you have good supplies of
CO2/nutrients.

Regards,
Tom Barr