10ppm nitrate wont be the problem, Until we see a pic how can we prejudge anytank!
with your cyano outbreak in your fuge and a limited sand bed in the display, i would think you are having some sort of nutrient overload from your sand and fuge.
For sure pics arent always needed but if every question started with a picture it would stop guess work to a degree .. Nitrate can vary from day to day but if its floating around 10ppm on a new test kit i dont see a problem, Not perfect but cant personally see it crashing a tank or causing it to start.
Ah pics do speak volumes! .. Nothing out the ordinary imo, White death?
Looks like healthy growth tips on the green slimer to me, i dont see any die back from the base.
Were these pics taken close to a water change? .. I see possibly carnage from a fish care to list what you have?
The white line on the monti is normal its just growth
I know you said your phosphates are reading 0 but that can be false. Do you know anyone who has one a Hanna tester? I know jim has one, maybe he can test your water.
x2...cyano/algae outbreak = nutriantsBINGO!
Cyano and other algae is a sure sign of high phosphate. This would effect your SPS and LPS but not the palys so much. Is it possible there is a pest messing with the palys?
Either way I would do a few good sized water changes and run a small amount of phosban in a reactor changed weekly until all algae subsides.