I've had enough Chetomorpha in the tank to fill two stuffed shopping bags, but it didn't have any impact.
A few times the thought has occurred to me to move it to the display
From what I've seen with the macros in my tank - having looked through the microscope at the sandbed for hours before and after the macroalgae was dropped in. To say there's 10x more benthic fauna of 5x as many species as without the macro likely severely understates the case. And I was going "dirty method" before the macros went in.
side note: weeks ago when the dino outbreak was young, I coudn't find any dino predators in the tank or the fuge, or skimmer or algae sandbed I cultured. Now, everywhere I look, every sample has a handful of different organisms eating dinos.
And the locations of dinos/cyano retreat and reappearance says that proximity to algae is a strong factor.
One could speculate the rise in Nitrates and Phosphates could be the effect rather than the cause of the dinos crashing and this instant signs of better tank health is something I've witnessed several times and reported in this thread.
Possible, but it seems really unlikely.
My tank had been holding steady at pre-dose numbers of 10+ NO3 and 0.20+ PO4 - last test on 3/4, with daily doses of 10ppm NO3 and 0.20ppm PO4. I continued this dosing along with feeding every day. I dosed and fed up to and including Friday 3/11,
Here's what my a section of my sandbed looked like on 3/11
https://goo.gl/photos/SgBdove54yMfqApT9
Light brown amphidinium/cyano dusting in the sand. Not mass globs of snot that would nuke a tank in die-off.
on Sat 3/12 and Sun 3/13 I didn't dose. I only had time to throw in 1-2 cubes of food and a couple of pinches of flake both days.
Then Mon 3/14 my sand is clean and my NO3 is 30, and my PO4 tests 0.50.
To put 0.50 PO4 in scale, my system is 245Liters (65 gal) so that's 122mg of PO4 or 40mg of P, which is the equivalent of 50g (dry weight)
Caulerpa or 890grams (2.0 pounds!) wet weight. I promise I didn't have a half a pound or a pound or two pounds of caulerpa - or anything else - die in my tank without my noticing.
It seems incredibly unlikely that I added 10 NO3 and 0.20 PO4 doses every day up through Friday, and then over Saturday & Sunday while getting a couple of cubes and several pinches of flakes my tank crashed N or P to zero so violently, it killed off something on the scale of a pound or two of living stuff and broke it down back into N and P in the water column by Mon.
It seems much more plausible, in my opinion, that in some tanks when algae/whatever "outcompetes" dinos into reduction - or more likely, reduction by slowing their growth below predation rate, it might be outcompeting dinos for elements other than N and P. Especially since a lot of the tanks in question are by their own admission trying to keep a "dirty" - high N and P - state.
Maybe we get fixated on N and P because that's what we can measure and control. (just look at my routine for example) There's a fairly common fallacy in science that probably has a name - "whatever I can measure must be the most important factor." But I think it's possible we might be missing that the real action shaping the composition of the algal community is trace elements - at least under "dirty method" conditions.
Like RHF said a short while back - 800 posts ago (!)
...I'm not sure that all of the successful treatments (or nontreatments) don't simply work because they take away something important to the particular species of dinos that you have.
People should remember that dinos, like algae and most photosynthetic pests need ALL of a source of N, P, Fe, many other trace metals, light, space to grow on, etc.
Take away any ONE of them and the dinos will be gone.
The trick is to find which of those is easiest to reduce while still permitting an adequate amount for other tank inhabitants (since they too need ALL of these).
Keeping a dirty tank and finding the dinos decline may simply mean high levels of bacteria that are present are out competing the dinos for some trace element.
