another cyano question

[gotnoidea]

i've followed all the posts on cyano questions and it appears a contentious issue... don't want to raise any further hackles but this is my situation:-

nitrate 2.5
phosphate 0.07
temp 80

all other water parameters are within norms.

i've got a heater (winter here in Oz) keeping temp at 80 & i've been doing 10% water changes every 2nd day. i have 2 PH's with wave cone heads working 24/7. i feed the fish every 2nd day & the tank equip is the best I could get. Still, I've got the cyano problem from hell.

i'd appreciate any new ideas you may have.....

(the heater is the newest add on - just 2 days old - prev water temp would vary maybe 4 degrees fahrenheit over a day)

thanks

[gotnoidea]

sorry - i should have also mentioned that I use a 5 stage ro/di water system so the water should be good....

[indy]

cyano has more causes than just 'trate and 'phate. You can be heavily skimmed, RO water, both at 0 and minimal lighting and still get cyano. More than likely because it isn't the same bacteria in every instance, just similar appearing. And so it will need a different remedy for each cause. I underskim, do 12 hour lighting, feed daily, use chaeto in my sump, RO filter, and haven't done a water change in months. I have no cyano. Several months ago, same setup but monthly water changes and I had an outbreak that I killed with magic white powder. I have no measurable bad stuff in my water now, and had none then. go figure.

[seaham358]

You have PO4 so that is a food source for cyno. Have you checked you ro/di top off water for PO4? You may need to add a 2nd DI housing to help filter out all PO4. I run 2 on my unit and it helps.
I have a phosban reactor and it has worked out well for me. There not much $$ and come with the first batch of phosban.

Any sign on PO4 is enough to help algaes and cyno to grow. So if your showing .07 there is a lot more becasue the cyno is using it to live abd you only see whet its not using.