Red Slime Algae (cyanobacteria) taking over my tank

[EvilTwin]

My tank has become a breeding ground for Red Slime. I have done a bunch of reading and it seems that there are some species of hermits that will eat the stuff. Other than that it seems to be hit or miss for most people. Anyone have any practical experience getting rid of this stuff?

[FragOutpost]

Red slime algae (cyanobacteria) can be a nusciance but it is also one of the easiest algaes to remove manually by siphoning with a 6' length of 1/2" vinyl tubing. I use the term algae loosely as cyanobacteria is really a bacteria and not algae. I have not seen anything that will eat cyano but according to "Algae: A Problem Solver Guide" by Julian Sprung blue-legged hermits (clibanarius tricolor) are supposed to eat it as well as the florida fighting conch (strombus alatus), but this has not been my experience. Is your skimmer running optimally? Are you running carbon? Have you tried increasing the flow in the areas where the cyanobacteria likes to grow? Cyanobacteria is also known to prefer water with lower alkalinity. There are antibiotics such as red slime remover but I would definitely recommend against them because they are designed to kill bacteria and will not discriminate against the types of bacteria that it kills wiping out colonies of certain beneficial bacteria as well.

[EvilTwin]

I took some time yesterday to really try to address this problem. I started out by using a hose to siphon the slime out into a bucket, but I didn't want to have to replace all the water I was taking out. So I grabbed a strainer from the kitchen and tried running through that. It worked for the most part, but there were still too many particles making it back into the water. I had some old whisper filter bags so I was thinking of what I could do there, but they were too small and the whole thing was going too slowly. What I needed was some kind of power-siphon-filter device. Enter my unused magnum 350 canister filter. I filled the carbon chamber and put a filter sleeve around it. I then configured the hoses so that the return was going back into the tank, being refiltered with the whisper filter. It that point things started working well. I moved from rock to rock, sucking slime from almost everywhere. I was pulling a lot off the bottom, trying not to suck to much substrate with it. Occasionally a small hermit or snail went for a ride into the filter only to be fished out later, none the worse for wear.

To further my efforts, I decided to change my lighting/hood assembly around a bit. Since setting up the new tank I have always had the glass plates that sit on top, just above the water. The 4' aqualight would rest on the top frame of the tank. The canopy would then sit over the whole thing. I decided to remove the glass plates, as I know this is better for air exchange and also would help let more light reach the tank. I had originally bought a set of legs for the aqualight to sit above the tank but never used them, thinking the canopy wouldn't fit. I tried them out and the canopy fits right over it. I also added an additional powerhead at the bottom of the tank pointing along the back wall to get some flow behind the rocks. I am also changing the food to try and see if that helps reduce the slime growth. I was feeding a flake food with frozen treats thrown in every few days. I'm now using only my frozen food to see how it goes.

When I awoke this morning, my tank was crystal clear and the usual scum that floats on top of the water was not there. The tank has a much brighter appearance. I must have stressed my cerith snails as I had 3 of them start to lay eggs yesteday while this was going on. on another note, I now have hundreds if not thousands of calcerous tube worms that have started growing on the back glass. They are the tiny ones and I suspect they are good for things, overall.

What I think I still need are two things: a mechanical filter of some kind and a sump. I stopped using my canister filter when I switched tanks because I had seen so much about them becoming nitrate factories. I know that when I used it my water was always crystal clear. As for a sump, I have acquired a 29g tank that I am thinking of using for that purpose. I would just need to build the baffles in and get a pump and plumbing for the return flow. I already have an overflow box (tidepool S.O.S.) that has yet to be used.

So there we go. I'll bet the slime comes back, but we shall see. I suspect that once it is in your tank it's there to stay.

[FragOutpost]

It sounds like you are well on your way to becoming cyano-free!
Removing the glass top was definitely a good choice. Your tank should run cooler now too. Have you looked into using a filter sock for when you get your sump set up? I know several people that have bought 2 filter socks and actually swap them out daily. http://www.marinedepot.com/aquarium_...ck.asp?CartId=

[EvilTwin]

Now, I know that the thought of experimenting on your tank would be unbelievable, but fear not, I am being safe.

In an effort to find a solution to my cyano problem, I was looking around for something that would eat the stuff. There are numerous webpages that talk about a species of hermit that comes from Mexico that really likes the stuff. Figuring it can't hurt to add a few more hermits, I ordered some up from Foster's and Smith. The species that is know to eat cyano is Clibanarius Digueti. Garf.org has a blurb about them and recommends and sells them.

Well, they arrived today, so...enter the experiment. I decided that before adding them to my main display I would place them all in a specimen box along with a small piece of live rock that had some cyano growth on it to see what would happen. I wasn't too optomistic, as they all just seemed to crawl around the bottom for a bit, but eventually, they started to climb onto the rock. I wasn't too sure what they were up to but at first I suspected they were just trying to reach higher ground or play king of the hill. After spending an hour and a half on a conference call, I checked the box, and sure enough, they had consumed nearly all of the cyano on the rock. I'm impressed. So I am left wondering one thing:

Did they eat the cyano because there was nothing else to snack on? I wonder if I put them in my tank, with they continue to prefer this for food. We shall see.

[FragOutpost]

Maybe they ate the cyano because they were that hungry. I've never seen any of my hermits touch the stuff. Maybe they were too busy feasting on other more appetizing foods. Glad to hear that they are working for you.