How to deal with possible blue green algae?

[WhistlingBadger]

I'd give it a couple weeks and see what happens, then make another change if necessary.

 

[Essjay]

Seeing that the nitrates sit around 10-15ppm, I don't do major water changes that frequently as I still want some nitrates for the plants

Aquarium plants prefer ammonia as their source of nitrogen. They only use nitrate if there isn't enough ammonia. Plants have to turn nitrate into ammonia to use it, and this wastes energy.
My tanks run at zero nitrate, or at least so low that the tester always reads zero. My tap water has 3 ppm nitrate according to my water supplier's website. Admittedly I have only 'easy' plants but they grow well even with zero nitrate.

 

[WhistlingBadger]

Aquarium plants prefer ammonia as their source of nitrogen. They only use nitrate if there isn't enough ammonia. Plants have to turn nitrate into ammonia to use it, and this wastes energy.
My tanks run at zero nitrate, or at least so low that the tester always reads zero. My tap water has 3 ppm nitrate according to my water supplier's website. Admittedly I have only 'easy' plants but they grow well even with zero nitrate.

If your nitrates are still high, you could add some terrestrial plants growing out the top. I hear pothos is especially effective.

 

[kieran01pd2016]

If your nitrates are still high, you could add some terrestrial plants growing out the top. I hear pothos is especially effective.

Coincidentally I did that about a week ago! Added a few stems of pothos out the side and they started rooting a few days ago. Hopefully that helps