From WTF to What the Hell my sand is changing color???

[rockbender]

I just noticed where I am not able to clean Sift the sand which is about 70% of the tank. From the side of the glass I can see the sand turning grey almost looks like a fungus or something
I had that salinity and ammonia spike last weekend.

I have had this sand bed for about 4 years. Just transfer from tank to tank. I did add about 20 extra pounds about 6 months ago.

Is this something to worry about should I change my sand?

One thing I am noticing after all these issues as of recent my skimmer just overflows and fills up in like 3 minutes with clear water.
The polyps and hammers that did make it are opening up not as big but are opening.
Maybe the sand bed going bad releasing toxins that's why all the issues? Too deep a bed for my setup?
The sand bed is a good 2-3" in different areas.
I can see the worm trails?
You can see the difference from left to right

OR am I worrying for nothing????

 

[ASERT]

Is there a window next to the side that this is on? I noticed this in my tank as well an only see it on the side where it gets hit by the morning sun, might have something to do with it.. That or maybe that's where the most detritus collects and there is not enough flow in that area...

 

[BeanMachine]

The spots are hydrogen sulfide (had to look that up couldn't remember what it was called) which is toxic and are caused by anaerobic bacteria... careful not to disturb that you could have another potential crash on your hands.

 

[BeanMachine]

Sand sifters would help alleviate that and prevent further pockets from forming. I would recommend a tiger tail cucumber.

 

[rockbender]

Tiger tail cucumber. Now where the hell do I find those. Lol. Well I have to make a run to Ontario mills tommorow maybe ill hit up a fish store out there.