Whats wrong with my hibiscus?

This thing was full of nice green leaves and beautiful yellow flowers. In the last couple weeks it has taken a turn for the worse. In 5 gallons of ocean forest in the greenhouse. Gave a light feeding a week ago when I noticed the yellowing. Any input on what's happening? Was a gorgeous plant at one point I'd hate to lose it.

hibiscus need more boron than most plants. try a hibiscus specific fert. I use some stuff by gardner and bloom.

Possibly pests. Can't tell for sure. But like mwoote implied it looks deficient from something

Not sure what's wrong with it, but they're one of the hardiest plants I've ever seen.... I've got huge ones all around my yard, 10-13ft tall probably, and they reproduce like an invasive species. If you were nearby you could come dig some up. I'm guessing that if you stuck it in the ground it would probably really take off.

I see a plant with its roots exposed and u wonder why its looking like shit? tell me it wasn't growing like that. I'll believe you

lol^ yea I'd add two gallons of soil to that pot. maybe heat things up with some formulated bokashi or mature compost