Still thinking if its diatoms or dinoflagellate. took some pictures or them.
what happen was that i left for an overseas trip for two weeks, in which my tank had already been running for 3 months. at that time my tank had only one clownfish and no corals. My ex-maid then without consulting me, overfed the fish. When i came back,I saw fish food floating around and my woodblock skimmer which is usually useless had foam which was very very dark brown!Thankfully my clown still alive> i did an immediate 40%WC and 10%WC two days later. Then i continued to do my 10%weekly WC. However, I noticed that these stuff started showing up. (which i strongly suspect due to high nitrates from the nutrients of the overfeeding. two weeks have passed and these stuff are still here. I did a 10% WC yesterday also but looks like theres not very much effect. Worst of all i recently added zoas into my tank which are very healthy but now i have no choice but to leave the lights on for their growth. My clownfish looks very healthy. any advise on how to get rid of these stuff. btw i only use pure distilled water from NTUC "LIFE". thx:)