sand covered in purple gunk WHY?

[Josh_22]

my white sand has always been on the brown side so when I was at the LFS i ask what I could do to whiten the sand and they told me to buy a white sand sifting star. And I did. He was right the star cleaned the sand and it was whiter then I had ever seen. Then the star moved to the back of the tank and all the sand in the front of the tank turned purple. way worse then it was before.
Why did this happen. I have a 3 to 4 inch DSB in my tank.
Thanks
JOSH

[djbh]

Josh,
cyano is the result of usually more than one thing.
Excess nutrients are one of them.Some sand sifting animals are a good help in ridding the tank of cyano.So are more frequent water changes.
The manual siphoning of the sand bed is another.
When you do siphon the sand be careful to only siphon out the top layer of the sand and not siphon out the living critters.
Lowering the tank water temp is also another one.
Higher temps seem to attract cyano.
Low alc levels seem to attract cyano also.
After cleaning the windows is a good time to do a small water change to rid the water column of algae.
You must have a nutrient export.
This can be macro-algae,skimming.
Be patient but get on it.
Is the cyano getting to a point where it creates a mat or carpet on the sand bed?Are there small bubbles on the sand bed?Does it seem to disapear or change color when the lights go out?
What is your tank parameters?
Lighting etc...
You need to tell us more for us to help.
Dan

[Canadian]

Your "White Sand Stirring Star" just obliterated most of the fauna you had in your sandbed. Congratulations! Now you have nothing in your sand to consume detritus other than your star fish and some bacteria. The reason it was "stirring" your sand was to find things to eat. So now you've got next to nothing to consume detritus in your sand and your sand bed's ability to process nutrients has been seriously compromised - hence the cyano outbreak. Lose the star fish . . . it's simple.

[Son Of Skyline]

What's your cleanup crew like? I had a problem with cyano also. Fighting conches and pearly jawfish solved all that right away! Well, all the jawfish really does is stir the sand, picking at it looking for pieces to reinforce his cave, but he's still doing the job. The conches are great too.

[titus]

Hello,

I never have this problem until my skimmer pump stopped. Ever since that happen there are some of these stuff here and there. It is actually quite a common thing to happen if 1) your skimmer ain't good, :( or 2) your skimmer requires cleaning, :rolleyes: or 3) you have no skimmer :eek: