Is this a diatom bloom?

[Fisshboy]

Hi all, been cycling my tank for a while now by adding pure ammonia to 4ppm, half live rock half dead rock, ammonia is sitting at 0, nitrite around 1ppm and nitrate over 100.

I have 2 T5HO one marine white one actinic blue on a timer for 8 hours a day and In the last few days iv had a huge brown looking algae outburst on the rock and glass and lots on the sand is this a bad thing? Iv never set up a saltwater tank from nothing iv always got established tanks so iv never had this before.

Thanks in advance

 

[oldrey]

That looks like à bloom to me, two ways off getting rid of it are
1 syphon some sand off but it will come back as this is a tempery fix or the best way
2 let it run its course, when the bloom goes it means that the silicone in the substrate has been used up to an extent that it cant support the bloom. Also if you are thinking of keep corals i would only consider soft ones with the lighting that you have at the moment. Hope this helps.

 

[Fisshboy]

Its going to be fowlr got a reef set up allready im using this for a puffer, i think im gonna let it run its course thanks for your help