1. Welcome to AquaScaping World!

    Become a register member to get FULL SITE ACCESS AND BENEFITS.

    Join the ASW community now!

    Dismiss Notice

cyanobacteria, N/P ratio

Discussion in 'Algae' started by peterko, Jan 22, 2011.

  1. peterko

    peterko New Member

    Jan 22, 2011
    Likes Received:
    My 600 litres tank is 1 month old.

    Water parameters:
    CO2 = 30 ppm
    Ph = 6,8
    NO3 = 10 ppm
    PO4 = 0,05 ppm
    Fe = 0,1 ppm
    KH = 100 ppm
    GH = 150 ppm
    (JBL tests)

    Lightning 270 w (fluorescent tubes), 12 h
    30% weekly water change (2/3 is RO water)

    At the beginning i had some problems with green algae, nitrates was 20 ppm therefore i lower the nitrates. Now cyanobacteria appeared but i dont understand why. According to N/P ratio there should be no cyanobacteria. I thing PO4 level is too low therefore i want to add KH2PO4 but cyanobacteria likes phosphates. Plant growth is not bad but i think it could be better.

    Hemianthus callitrichoides
    Eleocharis parvulus
    Pogostemon helferi
    Hygrophyla difformis
    Riccia fluitans
    Microsorium pteropus
    Anubias barteri

    7x SAE
    4x Discus
    30x Neon tetras

    Thanks for any advice.
  2. Garuf

    Garuf Moderator Staff Member

    Mar 22, 2009
    Likes Received:
    Leeds, England.
    Forget dosing and measuring. You'll never be happy if you do, especially as almost every test kit out there will be so inaccurate 40ppm could well read as 0ppm!

    BGA has 3 causes in my experience, low kno3 - the rarest but most easily fixed, low flow -40% of the time this is the issue, Dirty filter/substrate/insufficient filter turnover - the most common but also the hardest to address in terms of work because it means rolling up your sleeves cleaning the tank and filters more often and increasing maintenance all round.

    UK Aquatic Plant Society Forum • View topic - EI DOSING USING DRY SALTS
    This will help you get your ferts in order.

    In the mean time, carry out a black out, clean the filter and tank and cover with bin bags so no light enters the tank at all and leave for 3 days. NO PEEKING. Afterwards carry out 2 back to back 50% water changes and clean the filter.

    Reduce the light to 8hours max and increase your ferts and co2 this should sort the issues you're having. If not it's flow related so add more flow via a powerhead.

    Like I say at the start, stop dosing and testing and add more ferts. Algae are almost always limitations of something they're almost never an excess!

Share This Page

Sponsored link: