Carpet plants weird behavior

[Nurasama]

Hi all!

New member here, kind of a newbie so apologies in advance for mistakes - I wanted to ask something about a weird behavior of my carpet plants but allow me to explain the setup first:

Aquarium dimensions: ~200litres aquarium 100/45/50 (L/W/H)
Lights: 2 x ZetLight Lancia2 ZP4000-895PW 36W (set to 70% white, 40% red and 30% blue from 9AM to 4:30PM)
CO2: Yes (starts 2 hours before the lights turn on - drop checker shows green status)
Plantation: About 6-8 bushes of Micranthemum (monte carlo), java moss and anubius nano

The setup is fairly new, about 1.5 month after the cycle has completed and I bought some new pinetree looking plants from the local shop that they had hair algea on them. Long story short everything was covered in hair algea in the coming weeks and I decided to turn off the lights and CO2 for 5 days and also added Aquili Anti Algae for treatment. Hair algea was completely exterminated but I noticed that the monte carlos grew new leafs during these 5 days while with CO2 and lights on they have almost no growth at all.

Am I doing something wrong with the lights or the CO2? I just cannot figure it out why they behave like that..

Appreciate any feedback

Cheers!

 

[V1K]

I have done blackout a couple of times and yes, plants do grow in height during the time. It's not unique to aquatic plants either - have you ever uncovered any grass or other plant that's been covered with a bucket or something for a long time? They grow super long and thin - because the plant "hopes" that if it grows tall enough, it might reach light. But they don't really grow in dry mass, not being able to do photosynthesis. They only get longer using their present biomass and water.
Meanwhile, before the blackout they might have not grown much because, 1., there was no need to grow tall, and 2., the hair algae were competing for fertilizers and they might have been in shortage.