Cyano in new tank

[SaltwaterAussie]

Hi All...
I have recently set up a 180 gallon planning to be FOWLR tank, it has been running for almost seven weeks now. It has a wet/dry trickle filter and several powerheads for ciculation (turns over about ten times an hour), skimmer in sump producing a third of a cup brown skimmate daily.

I have at the moment about 100 pounds of live rock (been in for five-six weeks) and plan on adding a further 100 pounds in the coming months.

My tank when throuh the intial cycling stage (nitrite spike etc) when the live rock was first added and the water parametres are as follows and have been for a month.
SG 1.025
Ph 8.2
Nitrite- 0
Nitrate- 0
Ammonia - 0.5-1ppm

Why is my ammonia still detectable? (have confirmed results on another test kit)
I have not yet done a water change as I was told by my LFS to wait until my tank stabilises.
my diatom population is slowly decreasing but I am currently experiencing an outbreak of red slime algae (cyano), is this to be expected?
I have no inhabitants in the tank except for a crab and a couple of urchins and marco algae species that hitchhiked with the live rock, doing well and growing.

Should I be doing water changes now/ removing cyano?
What is causing the cyano? I cant see excess nutrients being a problem as there are no fish or feeding as yet.
Any ideas would be appreciated. :?

 

[reefrunner69]

Ammonia - 0.5-1ppm

Why is my ammonia still detectable? (have confirmed results on another test kit)

Hmmm, either something large in there is dead and decaying, or your still experiencing some die off on the rock. I'm not convinced that is an accurate reading, I think the urchins would have a problem with the consistant elevated ammonia.

Did you use tap water to set the tank up? If so did you dechlorinate the water with Amquel?

I have not yet done a water change as I was told by my LFS to wait until my tank stabilises.

Personally, I would so a series of larger water changes (siphoning the cyano as you go) using RO or RO/DI water. Cyano is expected in newer setups where the nutrients are high. Unless the new rock is completely cured whenyou add it, you can expect more of the same when you put the new rock in. However it is easy to cure rock in a rubbermaid garbage can or tub

 

[SaltwaterAussie]

Thanks for your advice reefrunner69... I went on a mission last night after I posted that message and pulled apart my live rock structure... I found a decaying ?sponge of some sort (about the size of a golf ball)... gross. It was jammed between two large pieces of LR. So you were right

Hmmm, either something large in there is dead and decaying

Hopefully my ammonia and cyano will settle down in the coming days.
Will do a 10% water change on the weekend.
Suprisingly even with the ammonia my 3 urchins are flourishing and growing well.
I havnt used any Amquel or simialr product.
Im going to buy another 50 pounds of LR in a couple of weeks... its a big tank to fill!!! Cheers 8)