It started in July 1999 as very small patches of cynobacteria growing on the rocks in my 180g tank. A common issue with newly setup tanks, the tank was about 7 months old. I used the common method of manually siphoning out the red slime off of the rocks. This went on for several weeks. During this time period I also fiddled with the skimmer assuming the red slime was a result of my ETS not being tuned correctly.

I went on vacation for 10 days and when I came back I had very large growth of cynobacteria. I attempted to siphon off the red slime and under it I found thick mats of hair algae and in some locations Bryopsis - a truly evil algae.

By the end of August 1999 the tank had about 20% hair algae coverage and red slime had proceeded to cover large sections of the sand. I tested a product called Boyd Chem-Pure which did a fantastic job of removing the Red Slime algae from the tank. I used it at about 80% of the recommended dosage. However, the die off of the red slime must have introduced a lot of organics into the water column as within days the hair algae growth was rampant. New York state was in the middle of a drought and I was limited as to how much and how many water changes I could make. I also had some issues with my calcium level falling down into the 330ppm range.

September 1999 the fight with red slime for the most part was over. However green hair algae got a very strong foothold. I was reaching 50% tank coverage with most of the right side of the tank was covered in algae but the left side of the tank looked pretty good. Manual removal was the only option as my Purple Tang and Sail Fin Tang had no interest in the algae. The draw back of manual removal is that it can get messy. Filaments of algae floated away and settled in other parts of the tank.

Figure 1: December 5th, 1999 - 10 days before snails added
Picture taken with Minolta 7000 SLR, 35mm, ASA200 Film, No Flash.

October 1999 I was still having low calcium levels and tank algae coverage had reached about 70% rock coverage and it started growing on the sand. Most snails were totally covered in it. In hard to reach areas I could see 6 inch long ropes of hair algae swaying in the currents. I purchased a Algae Blenny (Salarias fasciatus) to help with the fight. This fish had a good reputation for eating hair algae. However, mine showed no interest in this. I do have serious questions on the species of this fish as it differs from pictures in books. The hair algae smoothed my orange ball sponge. It was quickly turning white. I removed it from the system. This was the only invert actually lost during the battle. By this time I was spending about 4 hours a night three times a week removing as much hair algae as I possibly could. It just kept growing back. The drought was pretty much over but water levels were low. I was able to make a 30 gallon RO water change this month.

November 1999 I started to suspect my source water as part of the problem. I added a pressure gauge to my RO filter and it showed only 15 to 20 PSI. It should have been in the 30psi range (house pressure) with 70 to 80 being idea for RO filters. This was a clear sign that my RO filters were plugged. I tried to buy a RO booster pump from Reefers to help out with my pressure issues but various problems with Reefers prevented me from getting it. The tank had now reached about 85% coverage. Even my clam shells were totally covered, the overflow chambers were covered. It was growing in the sump it was just all over. My primary goal was only to prevent it from harming my corals. I purchased a 8" Red Sea Naso and a 5" Foxface to help out with the algae. And to my surprise they showed no interest.

Figure 2: December 5th, 1999 - 5 days before snails added
Picture taken with Minolta 7000 SLR, 35mm, ASA200 Film, No Flash.

December 1999 I was starting to question if I could save my corals. I needed to take some action quickly. All my budgeted money went towards fish like the Naso Tang, Foxface and Algae Blenny. None of them were helping to any extent. The Naso would pick at areas that I cleaned, but not enough to prevent it from coming back. I replaced the RO membrane and all of the pre-filters. I added my own custom DI stage using a Spectrapure DI cartridge. Rumor had it that Tiger Trochus snails would eat hair algae. Jim Fox (aka MiNdErAsR) and I split an order with Marine Center, we each wanted 20 snails. Well we had significant die off from the order and I only got 16. But I could clearly see that these snails made a dent. I figured snails would be the best solution for my problem. My booster pump finally arrived and I was able to start making 20 gallon water changes with RO/DI water. Within days the algae turned a brown color but never went away. Growth was reduced but enough that it was impossible to keep up with just manual removal.

Figure 3: December 21st, 1999 - 6 days after snails added
Picture taken with Nikon CoolPix 950 Digital Camera, No flash.

During December 1999, I assessed my current snail population and felt it was just to low. I had about 20 snails and 20 hermits left in my 180g tank. I made a decision to remove all my hermit crabs and put them in my sump. This would help protect the newly added snails. Trochus snails are knowing for falling over and not being able to right themselves. By removing the hermits they had a longer chance to survive until I got home and could flip them back over.

On December 15th I got these snails: 25 Nassarius snails (Nassarius sp.), 25 Baja Snails (Cerithium litteratum), 25 Margarita Snails (Nerita funiculata), 15 Astrea Snails, 12 more Tiger/Zebra Trochus Snails. I didn't use a formula or anything to get these numbers, just got as many as I could afford and still get a diversity of snails.

Figure 4: January 1st, 2000 - 17 days after snails added
Picture taken with Nikon CoolPix 950 Digital Camera, No flash.

Here you can see how effective the snails were in this single location after 17 days. No more manual removal was done after the snails were added except a few valonia bubbles. Apparently the snails were also eating the Bryopsis algae as by this time I was able to see significant deaths in the snails near patches of it. However, they did eat it and remove it. In fact in several spots this was the first type of algae to disappear. Each morning, and then when I came home, and then just before bed I made inspections of the tank looking for snails that died and for snails that needed to be flipped back over. If the Nassarius snails were eating a dead snail I let them have a good meal. If the dead snail was not being eaten it was removed to prevent it from fouling the water. The skimmer was closely watched and cleaned every other day as needed to keep it running in peak performance.

Figure 5: January 4th, 2000 - 20 days after snails added
Picture taken with Nikon CoolPix 950 Digital Camera, No flash.

This image is just 3 days later!!! By this time I just could not believe the progress these snails were making. I was telling several people on #reefs about the wonderful progress I was making and very few believed me. Thus I had the need to create this document. By this time the tank as a whole was back down to less than 10% tank coverage. The snails were getting everything spotless. The walls, overflow chambers, the clam shells were spotless, almost all of the sand was spotless.

Within a few more days the last few spots of algae seen above were completely gone. The tank as of this writing which was 25 days after the snails were added is down to about 5% coverage. Two little spots remain and I'm thinking about going after them manually. The snail population is down a lot. I don't have a death toll number, but I think I'll be ordering an assortment of more snails I just don't need as many now.