As for my peroxide Osti testing, it might be a few weeks before I have anything else since the summer brings maintenance work time when my testing space can be put off limits.
The question seems pretty dang straightforward: What level of single-dose H2O2 kills ostreopsis? (Can figure out multi smaller doses, and what else dies at those doses later)
It's not that simple.
Going to list all doses in ml H2O2 per Liter of tank water.
Did concentrations of .8ml/L, .7, .6 and .5
Found that in each beaker 100% of dinos had stopped moving by 30 min after, and many of the ostis lost their theca. I thought hmmm, I guess tomorrow I can continue testing lower doses, but I better check first to see if they somehow recovered overnight (I had read some stuff about cells repairing oxidation damage in the dark).
Next day, the dinos that didn't lose their theca had recovered overnight in all 4 beakers.
Quote:
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Originally Posted by Combined Exposure to Hydrogen Peroxide and Light
Toxicity of H2O2 under Various Irradiances.
H2O2 was observed to be toxic in the dark, but light enhanced its toxicity substantially ... The light-induced effect was most significant in tests with Microcystis (a cyano),where an irradiance of 500 µmol m-2s-1 caused H2O2 toxicity at concentration about 20 times lower than in the dark. Even dim light (10 µmol m-2s-1) caused a 5-fold increase of peroxide toxicity. Light-dependent toxicity was also observed for the other two tested species (a diatom and a green algae), albeit at much higher concentrations of H2O2 (Figure 2)
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I tried to attach the figure: column one is the cyano, , 2nd is green algae, 3rd is the diatom. Top to bottom is from zero light to bright light, the numbers in the columns are in mg of peroxide per liter to reach inhibition
So next the one question becomes 2: what peroxide level to kill ostis in the dark, and what level kills them in the light? And probably since I'm already dealing with what would pretty much be considered crazy peroxide levels for a tank, I'm just going to look into what levels kill ostis in a well-lit condition.
side note: I don't know if this is already recommended usage for H2O2 - I haven't gotten far enough in the peroxide treatment thread yet, but it seems like any application of peroxide to kill photosynthetic stuff should be done in bright light to reduce the amount of H2O2 required.