Another cyano thread!

[homer1475]

yes I know, another cyano thread! But for the life of me I cannot get it to go away. Pretty sure I've already tried everything on every other thread, but perhaps I haven't?

Tank is 5 years old, and recently(last year) I have had a persistent cyano issue. It clings to the rock, it gets matted up on the sandbed, and even grows on the glass. If I don't suck it out weekly off the sandbed it will mat right up into thick mats. Not having any coral issues, but it is unsightly.

I've tried increasing flow, increasing nutrients, adding bottled bacteria, used chemiclean which kills it for a week, but then it comes back with a vengeance.

As I know everyone will ask, tank parameters(extremely stable day to day):
Alk - 7.5
Cal - 420
MG - 1500
No3 - 4ppm
PO4 - .02 - .04 I try to keep this as stable as possible with daily additions of neophos
While I have not done an ICp test in a while, the last one(month or so ago) showed nothing out of the ordinary.

I have been reefing on and off for 20 years and have never had a persistent cyano issue like I'm currently having. Only thing I can possibly think of, which I have never done on the past, is to clean the sand I suck out during the cyano mat removal is soak in bleach for a couple days, then soak in RO/DI with prime for a couple days, completely dry out for several weeks, then when I have a big enough bag I dump it back into the tank.

Any help on how to clean this up would be greatly appreciated.

 

[Old Fritz]

How many times did you do a treatment of chemiclean?

In my experience if you have a really bad outbreak you may need to run it 3 times in a row and that has always worked wonders with me.

Any other method I have tried does not work as I have read things that even contradict each other and then you're left chasing nutrient levels.

 

[Sallstrom]

Do you have a picture of the tank?
Could be one of the tests show a bit high and you have low on either PO4 or NO3.
Or perhaps temp swings? Or have you changed lights or light schedules?

My first reaction is to leave it. Perhaps raise the nutrients even more and try to stay at those new numbers for a a month while keeping everything else stable.

 

[Jdgreef24]

It’s frustrating because when you question whether the nutrients are causing it, it brings feeding, aminos, dosing phos/nitro, water changes, bacteria, refugiums and light schedule in all at once and it’s very overwhelming. I’m currently trying the “feed heavier, good habits and just chill out” method but my tank is much younger than yours.