Green slime/cyano bacteria

I'm struggling with green slime in my 46 gallon. About 4 months ago a lost the white bank of lights on my led fixture. By the time I got it fixed I had an algae problem, both green hair algae and a green slime-type cyano. I got the lights fixed and have been doing the usual to get rid of the algae. Reduced lighting, increased flow, manually removed algae, frequent water changes, refreshed cleanup crew. The hair algae is gone, but the slime is staying strong. The water tests fine, no nitrates and very low phosphorous. There are currently only three fish in the tank. I run carbon in a canister filter and I've added GFO to this. After 3 months of no change I'm pretty frustrated and am close to pulling the trigger on pulling the fish and coral out, putting them in another tank and starting this tank over. I am not getting any enjoyment out of constant cleaning and looking at green bubbly slime. I've never had issues with this tank before, it was always very clean and almost maintenance free.

Any suggestions, anything I've missed? I'm cleaning again today, brushing the rocks, scraping the substrate, siphoning out removed slime, followed by a 20% water change. I've been doing this pretty much weekly. If something doesn't change this might be my last cleanout, then its lights out.

Do you have sand in your Set up? How deep? if shallow do you clean it? and what do you have for a clean up crew?

No, about an inch of crushed coral/aragonite.

What's your clean up crew. Conch's,Nass Snails,hermits,Spaghetti worms,pods,Ect.

More or less the usual clean up crew. Dwarf hermits, snails (turbo, cerith, astrea, nassarius), no conchs, plenty of mini brittles. Emerald crab. The turbos eat the slime, but nothing else does. I did notice that the crew numbers had dropped off so I replenished a couple of months ago. The tank has been running about three years, no extensive cleaning of substrate other than stirring the surface level once in a while and toothbrushing the area near the glass. Most of the substrate has rock sitting on it.

Crushed coral is Great for building up Debris, if I ever used Crushed coral I would always make sure I had Sand turners, I usually Ran 2 Nassarius Per Gal, 1 Conch per 10 gal, Digging fish as in jawfish for instance they dig, Diamond goby if you watch them they sift the rock there after the good stuff in your sand bed. you want diggers not sifters.

Okay, I took a siphon to the substrate I could easily get to.  This is the stuff in front, that does not have big rocks sitting on it, and is directly exposed to the light.  The cyano has been growing quickly in this area, and a little more slowly on the rocks.  I came away with two buckets of very brown water, so obviously the substrate has a lot of detritus built up.

Question: Do you think it is worthwhile to pull out the rest of the rocks in the tank and clean all of the substrate? I don't want to, it's going to be a pain, but will if necessary.  It does not have direct light on it, so the cyano shouldn't grow there, but the nutrients from that area could well be loading up the rest of the tank.

Point taken on diggers.  I was reluctant to get anything like a jawfish as there isn't enough substrate for tunneling or burrows. The pistol shrimp in my other tank has moved a tremendous amount of sand, but I planned for it and made a thicker base.

I was just using Jawfish as a type of digger fish, Yeah pistol shrimp, Conchs, sand crabs,Clams and lots of detrivitors,one would want in crushed coral,As for pulling all your substrate out and clean it that's not needed if you keep a strong clean up crew and lots of sand turners things should slowly get better.
but if you were to take out your substrate I would do it slowly not all at once to not to mess with your ecosystem and then I would replace it with a bit finer substance My self I use CaribSea, Seaflor sand it's coarse but fine enough for diggers to easily move and easy digging.

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I don't think he has crushed coral like you're thinking of Jim. His is sand but is more course than mine if I remember right.

blennieluvr wrote:I don't think he has crushed coral like you're thinking of Jim.  His is sand but is more course than mine if I remember right.  

So he has like what I'm using seaflor?

A little coarser than the Seaflor, but on that order. It is not what I would consider sand, I was able to use a siphon to clean it. I'm going to move some more rocks around today and clean some more. I did maybe 1/4 of the tank last time, I should be able to get to another 1/4 without too much problem.

Update on the cyano: Siphoning the bed really seemed to help. I moved some rocks and was able to siphon a lot of waste out of probably 2/3 of the bottom. I continue to get cyano but at a much slower pace, so I think I am gaining ground. I'll stay the course with physical removal and water changes, and maybe pick up some more turbos next time I'm somewhere they sell them.

Glad it's going better and thanks for the update. I have not battled cyano myself but have read that good flow helps. Sometimes even removing rock so there is more flow can be beneficial.