Another Dyno Question Here........

[MnFish1]

Agree! While dinos are most commonly associated with low nutrients, they aren't caused per se by them. Really low nutrients just give them a competitive advantage. I'm sure there are lots of different things that contribute to getting them...that's only one.

One of the things I'm seeing is the recent movement towards dry rock aquascapes. It's so rewarding to be able to create those beautiful scapes with dry rock but that seems to be associated with dinos every bit as much as low nutrients.

I had some Dinos - that just occurred after some coral areas of coral died. The Dino's showed up on the newly dead areas. I changed my oxydator yesterday - (which had run out of H2O2 almost) - and today the Dinos are 90 percent gone.

 

[taricha]

PS - it does though - take away from the theory that its nutrient levels that are a big influence on Dino populations right? I mean if the nutrients are the same as in the main tank - and now there are Dinos in the frag tank - this suggests to me - that its the new 'open area' that is the major determinant. Which is likely why in the threads of Dinos here - you can read 5000 different theories as to what to do nutrient wise. PS - I had some Dinos once - when I had a coral die off (due to a power issue) - I added a bottle of the coralline algae supplement - and within a month the Dinos were gone - replaced by purple corralline. JME - as always an interesting discussion...

Good thoughts. It's complicated.
Dinos being very mobile means that a lot of "dinos grow on X surface" are really observations about dinos relocating. (They do prefer rough surface to coral mucus.)
Our problem dinos double in slower than a day, so the sudden overnight appearance of dinos from zero to brown is not population growth but population concentration.

Surfaces, flow, light etc - all these secondary variables matter, and with dinos they become maybe not so secondary.

People make good arguments against the water nutrient idea for dinos, and I find them almost persuasive. But there are a couple of repeated observations that are just too frequent to explain away.
Water changes -> resurgent dino growth that had been flat.
GFO -> heavy incidence of dino appearance and re-appearance
(for a bonus: Amino Acids - > good dino growth. )

My best explanation for this is that under most tank situations dinos have good ways of getting the N and P they need, even in low nutrients (mobility, heterotrophy, toxins that create dead organisms for food). What causes the population to plateau is most often then trace elements (Fe).
In addition to the boatloads of anecdotes, some semi-experimental evidence for this.

So if the goal is to control dino populations through competition for trace elements, this is much easier to do at (modestly) higher PO4, NO3 than very low values.