question on actinics

[AdamN]

How much to actinics contribute to algae/cyano growth? I run my daylights for 8 hours, and my actinics for 10. I am wondering if maybe my actinics are on too long?

[kennyman]

I run my daylights for 11 hrs, actinc for 13 and have no noticeable pest algae.

I feel its all about what gets the available nutrients first. Either beneficial or desirable algae and organisms scoop up resources and space first or you get stuff growing you don't want. If you cut your lights back you limit beneficial growth too.

[AdamN]

good point, I will leave them as they are for now. I have done 80% w/c over the last month, and a few before that, and its only getting worse, its not nutrients, I have 0 nitrates, and 0 measurable phosphates and everything else tests and looks great. The problem I am having I have been told is cyano. Its basically a brown layer on the sand, which has now turned into long stringy stuff and moved onto rocks.

I have been told that my daylights if too old can cause things like this. I really dont get this, can someone shed some light on it for me? My daylights, I have no clue how old, I got them used and I have had them for 7 or 8 months, so I would say they are well over a year old. Could this be a problem, and if so, how? and why?

[groupie02]

I had cyano earlier this year and got rid of it by ensuring that I had enough flow and that I didn't feed too much. I did more aggressive water changes. I also changed my T5s which I got used when I purchased the tank. I also added some scarlet hermits which helped clearing the mess.

Everything is now looking good.

[AdamN]

I have done all of those things ... except change the lights, and mine is not going away. hmm ... I still dont fully understand the light thing, but I just might have to try it.

[Zoe]

I think the idea is that bulbs change spectrum when they get old.

[kennyman]

The cyano bloom seems to be the tail end of breaking in a marine aquarium. I think it is related to a blip of N that is the result of microbial activity deeper in the rock. We go through the typical ammonia, nitrite and nitrate spikes and we monitor and understand them. But there must be a fourth spike of byproducts as the anaerobic bacteria kick in. I think that fuels the cyano blooms.

The whole thing about lights could be explained with the idea that good lighting induces growth of other organisms which compete with cyano. The Symbiotic algae we want in corals are an example of whats swimming around in there. But I guess what your asking is how to make the balance happen faster. Like Groupie mentioned I kept my flow up, directed it a bit to make life harder for the cyano mats, kept doing waterchanges and waited it out. Eventually Coraline, other macro algae and new micro organisms began to take hold and replace the cyano bloom.

[AdamN]

Well thanks for all the info. I have now replaced them all with 4 new T5s and also added a Hydor for more flow.