old sand bed + new increased flow = Cyano?

Gyr

New member
I have enjoyed a very stable, mature SPS reef tank for years. I was able to resist the need to tweak things until about 6 months ago when I decided to increase the flow in my tank when my old vortech became unacceptably noisy. I replaced the vortech with two Jebao's (a pp20 and pp8) and was amazed at the increased flow compared to the vortech. Even on the lowest settings I initially had quite a bit of junk blasting around the tank that I never saw with the vortech. in a few hours that all settled out and I sat back and waited to enjoy all the benefits that high flow is supposed to bestow upon SPS tanks.
Well within a few days I started to see the red cyano bloom on the sand bed and since then it has gone crazy in my tank. I haven't had a problem with cyano for years, presumably due to the GFO and skimming and water changes that are part of my tank routine.
Cyano mystifies me, am I correct in my guess that stirring up the old sand bed with the increased flow is the cause? I prefer having a sand bed but if the only way to get rid of the cyano is to go bare-bottom I'd do it. I have been trying to remove as much cyano and detritus from the tank by blasting sand and rocks with turkey baster jets of water then cranking up the Jebao's and running the overflow through clean sump socks which I then remove a few hours after the debris storm has cleared in the DT. The tank looks better (not cyano free, but better) for a few days, then its back. I starved the tank and no lights for 3 days but no luck, cyano still there the next day.
Any suggestions, or do I syphon all the sand I can get out of the tank and go bare bottom?
 
Cyano for the most part mystifies everyone.. Many have opinions on the reason for its emergence but those are really all over the map and lacking any proof or consistency..

There is no need though to go bare bottom to stop it..
It likely could just be a temporary thing that will pass on its own..

A little patience/persistence is usually all thats needed ..Well and siphoning it out during water changes..
 
...There is no need though to go bare bottom to stop it..
It likely could just be a temporary thing that will pass on its own..

A little patience/persistence is usually all thats needed ..Well and siphoning it out during water changes..

I certainly hope so...my old Melanurus wrasse likes to sleep in so he wouldn't get his beauty rest if the sand bed were gone.

I'm not sure if this will work for siphoning cyano out of the fine sand bed: If I use one of those large bore (about 2 inch diameter) siphoning tubes and attach long enough flexible tubing to it so I can just run the water down into the sump through a clean filter sock, pinching the flexible tubing enough to minimize sand sucked all the way up the siphon. It seems that the sump sock would catch the cyano and other debris, as well as the sand that does make it through. Then I could rinse the trapped sand and return it to the DT the majority of the cyano would be discarded and the sock washed in bleach...is that sound thinking? Or would I just stir up whatever junk it was that caused the cyano to for min the first place?
 
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