Algae bloom or bacterial bloom?

  1. amelampus Initiate Member

    Ok, I have a (very) cloudy tank that I am trying to diagnose. I believe it is an algae bloom, but not 100% certain. The tank is fairly heavily planted so things have a greenish cast anyway, so makes it hard to tell. With all lights off it does seem very slightly green when looking through, so I am leaning toward algae. There is no significant new algae accumulating on surfaces (and it has been 3 days of the bloom) beyond the typical very slow deposits.

    Tank has been set up for 5 weeks. It has been cycled (used SafeStart+, then single fish-in cycle for 2 weeks, a few more now over last 3 weeks), but obviously is still "new". 56 gallons, Fluval 306, 2 coralife S lights (so quite a bit of light, since I'm going for planted, on for 11 hours). Chemistry is good -- 0 ammonia and nitrite, 20 nitrate, and has been for last 3 weeks (daily tests). pH is 7.0, with Gh and Kh still moderately hard -- I am slowly moving to RO water to reduce hardness and pH as this will be a tetra tank. 77 degrees.

    Bloom showed up 3 days ago, immediately following a water change and first "intense" gravel vac, but also following a dose of flourish (not excel, I don't add any CO2 right now. I dose regular excel as directly weekly). I also have flourish tabs under the root feeders. The reason I ask for help on algae vs bacteria is that the water was a little cloudy following vac so I put a polish pad ("micro filter") to clean it -- I *thought* that the Fluval polish pad would filter algae, but not bacteria, so...that seemed to indicate bacteria?

    Slightly green color, but not reduced by polish pad. Algae or bacteria? Any advice for dealing with either? My gut is to reduce lighting to 8 hours a day (don't want to do zero for long with the plants) and do a 30% water change...
  2. Pikachu13131 Member Member

    It sounds like a alegea bloom,I think these happen after multiple or large water changes(or that might be bacterial blooms).reduce our lighting and dont do water changes it will only make it worse.It should clear up in a week or two.