Spider mites I believe.

Agree - mites. Common problem with trying to grow indoors as well as outdoors.

NPK 19-19-19 once a week

Plus way over-fertilization which only contributes to the mite problem as they thrive on all the excess fertilizer. Spraying with compost tea, unless it is extremely well diluted first can also damage leaves.

Dave

Thanks for the replies. How often should I use the NPK 19?

I will look up solutions to tackle spider mites. I have been using solution which is a mix of dishwashing soap + Neem Oil + Water and spraying over the plants but either it doesn't seem to work or I may not be spraying it enough times.

Should I discard the plant or continue the sprayings?

I'd quit spraying the leaves with anything as coating the leaves only makes the problem worse.

It is one thing to spray plant leaves when the plant is outside exposed to the elements but indoors the spray coating only builds up and plugs the leaf pores.

And dish soap sprays unless carefully mixed and very weak can kill plants all on its own.

Instead just make up a diluted Neem and water mix in a bowl and gently wipe the underside of the leaves with a soft cloth dipped in it. That wipes off the mites at the same time.

But please understand that mites are very difficult to control/eliminate unless you use the chemical pesticides that are effective on them. So the plant may be a lost cause.

And yes, if you have other plants that are not yet infected, then I would toss this plant before the problem spreads.

Dave

Dave, thanks for the suggestion. I guess I am better off tossing off the plant and starting afresh.