Algae ID needed

[reefnewbee]

Need help in identifying this algae. In morning all rocks are almost clear but by evening tiny brown/red/yellow specks comes up and forms tiny bubble forms at roots. Sometime I noticed bubbles forming on sand.

Thanks.

 

[tektite]

Most likely dinoflagellates.

 

[Reefing Madness]

Yup, looks like Dinos
https://www.reef2reef.com/forums/re...-almost-impossible-get-rid-have-you-beat.html
How I beat dinoflagellates, and the lessons I learned ? Advanced Aquarist | Aquarist Magazine and Blog

 

[reefnewbee]

Thanks for the links. I was baffled why dinos should show up in my tank as I am very religious in water change and bio load in my tank is quite less (just two fishes and four corals few hermits and snails). But I think I made two mistakes which might have contributed to Dino growth: 1). I don't know why but I used only halide (white lights from my LED) 2). Alkalinity in my tank always stayed between 7 dKH-9 dKH and with difficulty my phosphate level stayed near zero.

Anyway from last one week I have cut lighting to half (just 4 hours/day).
Stopped weekly wc.
Cut back on feeding fishes.
Started dosing to increase alkalinity. Currently at 10 dKH - 11 dKH but plan is to keep it above 12 dKH.

I do see little less growth in dinos in four hours as they tend to increase tremendously after four hours of lighting. But they are not gone yet. I will keep you posted if I see any improvement.