Cleaning up Old tank- cyano problem

[Scubabum]

I have a 60 gallon tank that has been setup for 15 + years. Recently the tank was overrun with Green Hairy mushrooms, and other mushrooms. I removed a lot of the live rock and scrubbed the rocks clean. In the last week I have a Cyano outbreak. I'm using RO/DI water with 0 TDS,Salinity is at 1.025, PH 8.3, alk is 10dkh,Ca 400 ppm, Phos 0. Temp 79 The only thing I can think of is my lighting. My t5 bulbs are over a year old and I'm waiting for the new bulbs to arrive. Could this be causing my Cyano problem? Thanks in advance.

 

[acrohead500ppm]

You just stirred up a crap ton of nutirents, how old/ how deep is the sandbed ?

 

[Scubabum]

You just stirred up a crap ton of nutirents, how old/ how deep is the sandbed ?

Sandbed is about 2-3 inches and is 15+ years old

 

[Jim.mer]

Cyano

Cyano

Yes it could be your lights, Even the best tanks get it from time to time. Water changes, too bad that wasn't a 15 year old DSB but no biggie. Phos at 0 that's great. Maybe a little more flow and patience.

 

[Scubabum]

Yes it could be your lights, Even the best tanks get it from time to time. Water changes, too bad that wasn't a 15 year old DSB but no biggie. Phos at 0 that's great. Maybe a little more flow and patience.

I'm mixing up a water change as we speak. As far as Phos I'm pretty sure my test kit isn't the best. I must have phos if I have Cyano. Right??? I'm using mp10's for flow. Hopefully water change will help.