The Great Algae Genocide War of 2010….


Blenny Badlands
Hi everyone! First, I apologize for the extremely long post, but I believe it will help many people.

I wanted to use this thread to chronicle my efforts to eradicate the various algae outbreaks currently running rampant in my aquarium. I hope that this thread may help my fellow and future reefers avoid some of the mistakes that led to the state of my tank today. By providing a detailed account of the circumstances leading to my tank conditions today and the steps I am taking to correct this situation, other aquarists may be able to use this post for suggestions on battling their own algae outbreaks. Hopefully by the end of this post, I will have my beautiful aquarium back again. I would also like to quickly point out that the methods that work (or don’t work) for me may perform differently in your situation and I encourage you to research all your options thoroughly before taking any action on your own tank.

I should first start at the beginning. I set up my 125 gallon, bottom drilled tank last February, 2009. It was then that I made my first (and probably most influential) mistake: I filled my shiny new tank with 100 gallons of dechlorinated tap water. This was, of course, before I discovered this wonderful forum! Like most of my equipment, my lighting fixture was bought used from Craig’s List. It featured 3, 175 watt metal halide bulbs and 2 72” VHO actinic bulbs, one white and one blue. This sets me up for my second mistake….not immediately replacing the metal halide bulbs. I had no idea how old they were, and, at the time, didn’t understand that their light spectrum changes as they age. I figured, they were not burned out and cost anywhere between $50-120 per bulb to replace, so why do it now? I did, however, replace both actinic bulbs.


At the same time, I installed and set up my 40 gallon sump. Here’s where I made my third mistake (I think). In the refugium section of my sump, I laid down a 3.5” “deep sand bed”, which turned out to be too shallow to be of any benefit. Instead, I made a fantastic nutrient and nitrate trap. Likewise, I had installed a filter pad just prior to my return pump to catch debris before dumping back into the tank. These are also nitrate and nutrient traps. I also added a clump of chaeto and hung a 23 watt compact fluorescent light over it.
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I’d like to pause here to point out to any of you newbies…..the advice you receive from your local fish store SHOULD not be counted as gospel. Much of my early choices were made based on the information I received from only one local fish store in my area. Research all your questions from multiple sources, including books, articles, fellow reefers, forums, and fish stores so that you can make an educated decision on all that you do to your tanks. This is advice that I did not have in the very beginning.

Moving on. Still on day one of my tank set up, I installed a Reef Octopus 200 DNW recirculating skimmer and 2 Koralia 1 powerheads, facing each other across the tank (ok, all you experienced reefers, stop laughing!) I mixed my first batch of saltwater directly in the tank, since there was nothing else in there. Next, I added 4 50lbs bags of live sand. I later found out this was more of a financial mistake than a health risk to my tank, since you don’t need both live rock AND live sand. Dry sand will eventually become “live” on its own. The next few days I had a very cloudy tank. Once it all settled, I then added my first 50lbs of rock. I added another 50lbs the following week, then a final 50lbs the third week. Here was another minor mistake…I should have added even more live rock for added filtration but instead went with the bare minimum recommended live rock quantity for my size tank.

I then waited 2 months for the tank to cycle, testing ammonia, nitrite and nitrate frequently, first with test strips, then with liquid test kits. Once all my parameters were in check, (end of April) I added my clean up crew and my first fish, 5 Blue-Green Chromis. 2 died in the first week, the other three survived nicely. One month later (by month 3) I added my second fish, a long fin banner fish. It lasted a month. My 4 peppermint shrimp also did not fare well and all died in about 2 weeks. I also upgraded the powerheads to 2 Koralia 3s. Here is another mistake I should point out. When you have a 125 gallon tank, you can easily maintain about 150-200 various hermit crabs and snails. My measly contribution of 50 could never hope to keep up with that kind of workload.
I went about 2 more months of relative stability, adding a couple more fish, 5 weeks apart, as recommended. However, I noticed that my chaeto just would not grow. It kept getting bogged down by red slimy algae (cyano) and I could not keep it clean. I started using RO/DI water by the beginning of June. Which means, the first 5 months of operation I had been using the tap water.

By about September, I started to see some hair algae showing up on my rocks. By the end of September, I had added a Foxface to my population to help eat the algae. By this time, I had 3 chromis, a dragon goby, a diamond goby, a lawnmower blenny and a hippo tang, 2 skunk shrimp and several red-legged hermits and turbo snails. However, it was also about this time that I started to notice a decline in my clean up crew population, particularly evident by the numerous empty turbo snail shells. I added about 20 more crabs to also help with the algae. At this point, I was doing 30% water changes about every 4-5 weeks.


The blenny died after only 3 days of munching the algae off my rocks. At least, I assume that it died, since I never found the body. Thinking it was just a bad fish from a bad store, I bought another within a week from a different store. That one lasted 7 days. “Blenny Badlands” was thus added to my forum signature. Not knowing what had been the demise of my blennies, I kept chugging along. So many times, a fish just mysteriously disappears without reason. I figured this was one of those cases. I was not recognizing the pattern that was beginning to emerge here.

Since I wasn’t having much success with the algae eating fish species, I intensified my cleaning efforts, adding several toothbrushes to my tool belt. I began siphoning the surface of the sand, wiping the glass, brushing the rocks, reducing my lighting, and reducing my feeding schedule to once every three days with frozen foods only (eliminating flakes from the menu). I had also been slowly introducing some corals into my system, including some mushrooms and pipe organ corals.

In October, I once more decided to try a blenny, but this time went with the Starry Blenny. Like the ones before it, it started eating quite vigorously throughout my tank, but met his demise in less than a week. I scratched blennies permanently off my list of species to have in MY aquarium. By this time, I was having a hard time finding any crabs that weren’t just empty shells on the bottom.

At this point, I began to get suspicious. At first I thought maybe I had an unknown predator in my tank. Of course, I was thinking more along the lines of little critters as the culprits. Unfortunately, I wasn’t far off the mark, just had to think a little smaller. In mid October, I added a sea hare. He seemed to plow right through the algae, and managed to hold on for 3 weeks before joining his other algae-eating buddies down the porcelain express.
By now, I was really starting to worry about some sort of toxic algae. I began to take the rocks that seemed to have the worst algae growth out of the tank to scrub off in buckets, rinsed really well, then returned to the tank. I tried to do this gradually so as not to stress the fish too much. It was around this time that my Foxface wasn’t looking too hot. He seemed very lethargic and not too interested in the nori in the veggie clips. I removed him to the QT, where he slowly wasted away.

At the end of October, I tried my first black out. It lasted a week, with the tank covered in a heavy blanket. I did a 30% water change at the end. This seemed to help a little, and I was encouraged. Combined with my individual rock scrubbing, it looked like I was finally starting to gain some ground.
Start of November, I built a DIY algae scrubber and installed it on my system. With all the hype about it, I thought that this could really help! I was encouraged by the early growth on the screen and cleaned it precisely on schedule. However, I wasn’t seeing any green growth after running it for 2 months and my nitrates didn’t budge from their 20ppm readings (API liquid tests). I was also down to almost no detectable clean up crew. They were dying faster than I could replace them.

Thinking maybe some of the problem was originating from the refugium, where all sorts of strange algae was growing (except my chaeto, of course), I decided to remodel the fuge by cleaning out all the gunk and adding some live rock. I was extra cautious not to disturb my “deep” sand bed. I threw out the old chaeto and replaced with a new clump. I added some turbos and some hermits to the fuge to help keep it clean. This was the beginning of January, about 1 month ago.


This is when my dragon goby bit the dust. He was one of my first fish. I was so disappointed to see him go. He was always snatching little mouthfuls of hair algae off the rocks where it was starting to grow longer. Shortly thereafter, my railway goby also passed away. He was filtering all the sand in the tank. I added 10 nassarius snails to my display tank to attempt to keep the sand turned a little bit. About 3 days after rebuilding the refugium, I spent a frustrating hour trying to catch a coral beauty in my display tank. Eventually, I had to remove a good portion of the rock to get it out.
I decided at this time to do another round of rock scrubbing in the buckets. Since so much rock had been moved, I decided to rearrange the overall rockwork in my tank. This involved moving some of the base rocks that hadn’t budged since they were first laid in last February. Here, folks, was probably the straw the broke the camel’s back. Turning over rocks and exposing surfaces that have been buried in the sand in all probability stirred up a whole bunch of trapped detritus and nutrients. This made my algae battle equivalent to trying to put out a house fire by hooking your hose up to a fuel tanker.

In the two weeks that I made that change, I have diatoms in my sand. I have red cyano smothering my corals. I have hair algae of 3 different colors blanketing my rocks, and----here’s the coup de gras guys----dinoflagellates all over my cords and glass. Here is where I realize that the dinos, the TOXIC variety of dinos, has been present in my tank all along. It has been slowly (or quickly) poisoning anything and everything that preys on it. Here is its mortality list:

2 lawnmower blennies…………….$20 a piece
1 starry blenny…………………………$25
1 Foxface Lo………………………………$45
2 diamond gobies……………………..$25 a piece
1 railway goby…………………………..$35
2 dragon gobies………………………..$20 a piece
14 Mexican turbo snails…………….$42
62 red legged hermit crabs……….$124
1 sea hare………………………………….$20

Total Death Toll = 86 animals, $421
Now that you have a complete history of my aquarium, and all the mistakes that I have been able to identify so far (I’m sure there are others, I just didn’t point them all out!), I’d like to lay out my strategy for eliminating the multiple algae species in my tank. So here goes. Starting this Monday, the 22nd of February, I will begin a 12-day complete blackout period on my tank.

Day 1: This involves unplugging all my lights (including the fuge lights) and covering the tank itself in a heavy blanket to eliminate ambient light. While the lights are off, I will be removing my lighting fixture in order to repaint the reflector a brighter white and to replace the old MH bulbs. I will also be adding in 2 more powerheads, Koralia 4’s to increase my water circulation in the tank. I will also be hooking up my dual carbon and GFO reactor to my sump. I will also collect and remove as many invertebrates as I can catch and placing them into a separate tank/tub for the duration of the blackout. This should be easy, since I really don’t have any left. I fear a rise in nitrates/phosphates/ammonia as the algae begins to die off and is no longer absorbing these things from the rock or the water column. Begin the kalkwasser drip to raise PH and keep it high (8.6) for the duration of the blackout. Finally, I will be removing the sand bed from my fuge completely, cleaning all the sump components and equipment, and filling the fuge chamber with additional cured live rock for added filtration.

Day 4: Complete a 30 gallon water change, approximately a 25% change. Check on all livestock for illness, or death. Test all water parameters. I will also be thoroughly cleaning all my equipment at this stage, to include the main return pump, all powerheads, the skimmer, and the heater. Once complete, the blackout continues for another 4 days.

Day 8: Complete a 30 gallon water change, approximately a 25% change. Check on all livestock for illness, or death. Test all water parameters. At this time, I will also remount my repainted and refreshed lighting fixture, which has allowed it a total of 8 days to ventilate and fully cure.

Day 12: Complete a 60 gallon water change, approximately a 50% change. Check on all livestock for illness, or death. Test all water parameters. Cease the kalkwasser drip. Add 100 more pounds of cured live rock. PRAY that all this effort was worth it! Turn on all lights. Inspect for algae areas. If serious algae still remains, go to plan B- remove all livestock, remove all water, boil all rocks, sand and equipment, START OVER. Let’s hope plan A works!
There is some confusion over the water changes. Some information is to avoid water changes entirely during a blackout and hold out until just before you turn on the lights again, and do a much larger (up to 90%) change. Other information suggests that you do smaller water changes (10%) every day. I am going with the happy medium here of 30% every 4 days until the final, 50% at the end.

Thanks for reading this far!! To make sure I start off right, here are some of my BEFORE pictures. I hope the AFTER pictures will look nothing like these!








I will continue to update this post with my progress and will post pictures of the things I am doing. I welcome your feedback and suggestions, as always. I hope my experience can help some of you fight your own algae battles! Good luck to you and good luck to me!
Are you blacking out the algae scrubber also? Will the gfo be enough filtration to reduce toxins? Just wondering dont have either of those yet to be honest was thinking of doing a scrubber in the next few weeks. No plans for a gfo.
Are you blacking out the algae scrubber also? Will the gfo be enough filtration to reduce toxins? Just wondering dont have either of those yet to be honest was thinking of doing a scrubber in the next few weeks. No plans for a gfo.

Yes, I am taking the scrubber offline altogether. It doesn't seem to grow anything but reddish brown slime. Not the think green mat that I am supposed to have after 3 months of use. And I am also not seeing any reduction of algae growth either in the sump or in the display tank. If anything my algae is getting worse. My nitrates are sill registerting at 20ppm, the same as when I started it.

I believe that the scrubber could be larger for my current tank situation and I could use more light power, but there is no way I can fit a larger scrubber or more lights under my tank. The stuff in my main tank is too healthy and the nutrients too prolific for the scrubber to really make much of a difference.

Quite frankly, I am of the opinion that I gave it a try, its not helping ME, so I'm going to focus my attention and efforts somewhere else.
I noticed my chaeto would not grow unless it had strong light AND the light was pretty close (a few inches) to the chaeto. Once I did that it started gorwing like crazy. I have to cut it back weekly now.