You want the limiting factor to be light, not ferts or Co2. You can have too much of both the latter with no problem, as long as your light isnt more than what your plants can use. Plant density plays a big role there too. The more plants you have, the more light the system can tolerate. I would try only 2 bulbs for a while (if possible) and definitely raise it up some. 15-17" is incredibly close to have T5HOs.
Good advice. I just removed my fourth bulb two days ago and things seem to be doing a bit better. If the tank continues to be imbalanced I will remove the 3rd bulb. As far as lifting the fixture up: this isn't an option. My family doesn't want me drilling holes in the ceiling to hang the fixture.
The dosages you're using seem to be off. The following would be the recommended amounts for 35 gallons.
KNO3 1.6 gm (approximately 1/4 teaspoons)
KH2PO4 246.8 mg (approximately 1/32 teaspoons)
Plantex CSM+B 1.gm (approximately 1/4 teaspoons)
Optional (usually not necessary) 650mg of K2SO4
Since you already have 30ppm of nitrates your KNO3 is fine. I would not increase them to what I listed above. Since your tank is apparently producing nitrates it is most likely also producing phosphates. That is the one thing you are dosing more than enough. Do you have a test for phosphates?
I would personally continue the KNO3 dose, reduce your phosphates and dose the K2SO4 as listed above. That's about it for dosing. easy peazy stuff.
Reducing you light by raising the fixture or reducing the photoperiod would be a wise choice. However, greenwater can also be caused from an increase in ammonia. Your statement "Doing about 40-50% gravel suck water change per week." leads me to believe your are regularly disturbing the substrate. This is a great way to increase ammonia and cause an algae bloom.
I was using lowered amounts of the ferts because my tank in the past seemed to be imbalanced. Maybe that was because of the light.
The values you gave me are for a 35g, I use a 38g. I can use "another nutrient calculator" to calculate the amounts I guess. Though I believe I should greatly lower nitrate (for sure about nitrate lol) and if you say the tank is producing phosphorus too then I guess I will lower phosphorus a bit too.
As for my water changes: I suck the algae and detritus off the soil and plants but I don't actually disturb the soil. I just said gravel suck because I didn't wanna go into detail about it... Sorry for the misunderstanding.
I have a UV sterilizer running for 2 hours a day because I had a green water issue a while ago. It may have been natural sunlight because I didn't gravel suck back then to cause ammonia spikes.
I do have a decent amount of plants in my tank but they haven't accumulated much biomass.
EDIT: Also I found out that I may not have waited the full 5 minutes for the nitrate tester to react fully and the nitrates seem to be at 35-40 ppm in the morning (the color changed after seeing the test tube the next morning). So I got 35-40ppm with a dose of about 0.6 grams. I think I will lower it to 0.4 grams, I can test to see how this goes.
And for the phosphorus: Cyanobacteria is apparently caused but abundant phosphorus. Lately I have been dosing a bit more than recommended because I heard that higher values have been tested to have positive effects on plants... However, in this case since phosphorus is being produced I will lower my levels from 0.33 grams to about 0.20 grams.
Second to last I have the K2SO4 which is optional? On dosing regimes I usually see it, especially for EI. Regardless, I lowered the value from the 2.4g recommended to 1.2g... I have no idea what to do on this one nor do I know what detriments there may be by overdosing.
Lastly is CSM+B which contains iron. On the nutrient calculator they recommend about 1.1 grams of it. I have a good amount of red plants in my tank so I like dosing a decent amount of iron. I've been dosing about 3/4 of the recommended amount at 0.7 grams.
What do you guys think about these numbers?