Phosphate And Algae

  1. Awaken_Riceball_ Member Member

    I am reading conflicting information regarding PO levels in the aquarium and the relations to algae. The conflicting information is that GSA appears because of low PO levels ( 0 - 1 ppm); however, another website states that PO does not cause algae because he has high PO levels ( 5 - 10 ppm ) without any algae bloom.
    Other websites states recommended PO levels to be between (0.5 - 1 ppm) and others state higher between (3 - 5 ppm).
    I am lost due to conflicting information in where the PO levels should be to get rid of GSA. Also, will high PO cause algae.

    Currently, the PO level is as stated:
    Tap Water = 0 - 0.25 ppm (hard to tell the difference).
    Aquarium = 2 ppm

    Thank you for any information!
  2. leftswerve Well Known Member Member

  3. Awaken_Riceball_ Member Member

    Yes, that is true, but it is confusing when reading that PO causes algae, increase PO to remove GSA, keep PO < 0.5 ppm, etc. I am trying to find out what is a good PO level for adequate plant growth and does increasing PO leads to more algae growth?
  4. leftswerve Well Known Member Member

    According to Seachem: "The ideal phosphate level will vary, but generally ranges from 0.15–1.0 mg/L"
    All I am saying is that you probably need to be looking at photosynthetic periods as a source if you keep your phosphates in check.

  5. Awaken_Riceball_ Member Member

    That is great! Thank you for sharing that information!
  6. Jocelyn Adelman Fishlore VIP Member

    I aim to keep phosphates between 1-2. Low phosphates definitely contribute to GSA. Below 1 I get gsa, above I'm totally clear...

    However to complicate it all more, there is a "magical ratio" of phosphates to nitrates. So of phosphate low/nitrate high or phosphate high nitrate low its no good... don't as me what the actual ratio is, don't remember :( though I'm sure that looking at decent fert formulas (nilocg thrive or UNS plant food) you could figure out the optimal ratio and then dose accordingly

    I usually keep nitrates between 20-30 (range 10-40) in my tanks, if the drop below 10 I have issues...
  7. KeeperOfASilentWorld Well Known Member Member

    Any P not taken by plants will directly cause your algae spores to bloom. If plants take in all P, then it will be even better then the scenario in which you don't have any P because you would have faster growing plants. ADA keeps P below 0.2ppm and EI keeps P between 0.5ppm and 2ppm. Hope this helps.

  8. DoubleDutch Fishlore Legend Member

    Not all fertilizers contain nitrates and phosfates. A lot are free of those.
  9. DoubleDutch Fishlore Legend Member

    Jocelyn is right. NO3 and PO4 should be available in a certain ratio. I am.always told 10 nitrates to 1 phosfated. A shortage of one of both causes algae (or shortage of other needs like light, CO2 and microfertilizers.)

    Beside of that not all kind of phosfates are usable for plants (depending on the stuff with which it is in a chemical connection)
  10. Awaken_Riceball_ Member Member

    Good information! So, it would seem that my Phosphate is lacking because my nitrates is definitely within the same range as yours.

    Interesting, and I will test my phosphate everyday for a week and see what I need to do. Since my nitrates are within 20 - 30 ppm. If the ratio is 10:1 nitrates to phosphate, then I can test that by dosing phosphate to get it up to 3 - 4 ppm.

  11. Jocelyn Adelman Fishlore VIP Member

    I wouldn't bring phosphates up that high.... aim to keep it between 1-2.
  12. KeeperOfASilentWorld Well Known Member Member

    Dear @Awaken_Riceball_ ,

    A lean phosphate regime should almost never cause any issues with algae. You should be thinking about Potassium ( K ) levels instead of P. K is also the variable which promotes the nitrate intake of the plants. In my opinion, you should be aiming for a daily value of 3.5ppm K with lean P values ( below 0.2ppm ) and lean Fe values ( below 0.1ppm ) until you resolve your issues. After your tank stabilizes, 0.5ppm Fe and 1ppm P should be your maximum values to keep everything stabilized. I think the problem you are experiencing is almost certainly caused by a low K dosing together with low and/or not stable CO2 injection.

    Here are two helpful videos from Dennis Wong :

    You could also find that his 2 videos on CO2 injection are very educational. If you like his style, I also advise giving them a look.

    Hope that I could help.

    Happy Fish Keeping :)
  13. Awaken_Riceball_ Member Member

    Thank you so much! Highly informative! I stabilized the pressurized CO2 using the drop checker. The drop checker is consistently green. I will look into buying dry or liquid potassium and try to keep phosphates within a reasonable range. I will change my dosing and keep it up for a month to see what happens.