NO Algea Grow In My Ccichlids Tank!

hi. My name is aga. I keep Tanganika Cihlids. I have got NO ALGAE GROW in my tank.
My tank description-
360 litres tanganika cichlids, drilled tank 3.5foot x 2 foot x 2 foot (ex saltwater) with 75 litres sump.
biological filtration-Sump filled with pot scrubbers and  JBL BIO Nitratex
mechanical filtration - filter sock with sponge  and 2000 lph return pump
chemical filtration - Seachem Purigen and Seachem Matrix Carbon
 light- Day Lights Marine Led lamps
substrate - CaraibSea Arragonite OOlite Sugar Sand
plants- 10 anubias, 6 cryptocoryne , 2 java fern
addictive- Easy Life Easycarbo and Easy Life ProFito Liquid Fertilizer. (I adding very very little of this stuff, not even half recomended dose every second week)
water parametrs- ph 8.1 -8.2 , nitrite 0, ammonia 0, nitrate 10-20 ,
I feed twice a day (sometimes ones a day) New Life Spectrum Pallets and flakes, and Tetra Fresh Delica Daphinia(zel).
20% water change every week
15 small cichlids
Tank is running 6 months plus 2 months fishless cycle with shrimp, so 8 months all together!
Not sure what cause lack of green algae in my tank? I use tap water ,which is high in nitrate -35 ppm, so my tank got less (only 10 -20 ). My plants are doing ok- My anubias is attached to driftwoog and I see how fast roots are growing..cyprocoryne tropica is doing fantastic , mioya not so great but ..its growing. Why not green algea?
Pls have a look on photos of mine tank. can someone halp me?
thank you Agnes
English is not my first language, so I am real sorry the  grammar.