What are these stringy things?

[Finless]

My tank is a 4-month old biocube 29.   Water parameters are ok.   All are Salifert tests.

NO3 <5ppm; PO4: Undetectable; Alk: 8.9; CA: 420; Mg: 1350

Livestock: 2 clowns, 1 six-line wrasse, 1 royal gramma, 2 pink-striped gobies, 1 cleaner shrimp, CUC: 20 small snails, 20 blue-leg, 5 scarlet-leg hermits.

Filtration:  Lots of cured dry rock, Tunze 9001 skimmer (about to be replaced with Icecap k1 nano), SeaChem Phosguard, SeaChem Purigen.

Circulation:  Icecap k1 at random pulse up to 70%, 660GPH eFlux wavepump at 100%, 0.5sec pulse.

Lights:  Bluefish mini controlled LED, at Midday from 1pm-7pm: 6 cool white at 22%, 6 Royal Blue at 70%, 6 Blue at 70%.

This morning I notice there are these strings that have the fine sands stuck on them.  In the pic, they are at center, on the rock, and below the rock. 

Has anyone seen anything similar and know what they are?

I'm worried because I also found that there are signs of red cyanobacteria.     If these strings are also bacteria, maybe I'd just nuke them all

in one shot with ChemiClean or UltraLife.    20% waterchange is scheduled for the end of the week.    Thanks in advance for inputs.

 

[patback]

I THINK I see what you are talking about. It may be a slime trail from a nassarius that sand got stuck to?  

[Finless]

The guy at LFS also said he thinks it's snail slime.

[mcarroll]

It looks like you're using a ton of filtration and driving your phosphate level into the dirt, causing pest algae to prosper in the process.

 

Filtration should be no more than a skimmer right now.

 

What you want is to see green algae and/or coraline algae growing.

 

Those algae both require nutrients just like corals do, which means that your nitrates and phosphates both need to be in the positive.  >5 ppm nitrates and >0.03 ppm phosphate would be good minimums.

 

Increase your snails (herbivores only pls) as your growth of algae increases.