Small brown tubes coming out of sand

[sunil1111]

Hi,
I have a 75 gallon salt water aquarium. Three months back all my damsels and clown fish died. They didn't show any symptoms. They used to swim freely and when I come from office and see, I can see them dead and floating on the surface. This went on for 3 weeks and stopped and left me with couple of tangs, puffer fish and foxface. I took my aquarium water for testing and they said everything looks normal. Then I looked my aquarium thoroughly and saw small thin brown tube like things emerging out of sand which i never saw before. Recently I added 4 green chromis and one died the same way. Please somebody help me regarding this. Below the some pictures .
Thank you
Sunill
http://s14.postimg.org/aafp9zz8t/image.jpg
http://s24.postimg.org/jjqox3yc1/image.jpg

 

[mr llimpid]

Sorry pictures are to small to see. Need to provide more info, age of tank, readings of all test, do you use RO water, filtration you have, do you have power heads and how many, temp. of tank, what you feed your fish and feeding schedule. Also please provide full tank shot, just insert photo on here.

 

[sunil1111]

Here you can find better pictures.
http://www.reef2reef.com/forums/reef-aquarium-discussion/128185-small-brown-tubes-coming-out-sand.html
Age of the tank - 1 year
Filteration - Cascade 1500 Cqanister filter, media changed every 4 months.
I have 1 power head.
I prepare water myself using tapwater.
feeding two times a day ( spectrum pellets)

 

[saxman]

Looks like you have a very deep substrate...are you running a DSB?
Have you reached in and pulled one of the "tubes" out? I'd do that and see what's on the other end if anything.
It could be snail siphons (personally, I think this is it), might be some kind of tube worm, hydroids, etc. Can't really tell from the photos.
Are you keeping any Olividae or whelks? These snails bury themselves in the sand and poke their siphons out of it. They're also predatory.

 

[mr llimpid]

I personally would change my media every month and rinse or change the prefilter media every 2 weeks. I would stop using tap water and use RO water (you can buy it from local grocery stores or wall mart). Feed more verity of foods, like mysis shrimp and nori and veg. frozen foods for the tangs and fox face, the puffer needs hard shell creatures to keep its teeth filed down. You need to have your own test kits, just the basics, ammonia, PH, nitrites.

 

[sunil1111]

@ Saxman: the tubes are just 1-2 cm. When i use the syphon while cleaning the aquarium, those tubes easily come out of sand and collected in the waste water bucket. I will post the picture of them later today. The height of my sand is about 1.5 to 2 inches.
@LLimpid Thank you for your advice. I will look into the things which you mentioned.

 

[saxman]

If what you're getting are just "tubes", they likely have worms or hydroids in them. Do you ever see anything poking out of the tubes?