Green algae for Otocinclus catfish  9/29/08 Dear Crew, I have had 3 Otocinclus catfish since May 2008. While they were being quarantined, they learned to eat zucchini, but they never took to algae wafers or Nori sheets. After their quarantine period, they moved to my 55 gallon tank, which has lots of brown algae and green spot algae. They are all very fat, very active after dark, and generally very healthy looking. I still feed them zucchini once or twice per week, but they never touch it. As far as I can tell, they are living off the algae in my tank. <Certainly possibly in large aquaria, especially if they also consume small amounts of flake food and other "leftovers".> I thought all was going well, until I came across the following information at your website (http://wetwebmedia.com/FWSubWebIndex/otofdgf.htm): "Otocinclus really don't eat anything much besides green algae and the microorganisms therein. Brown algae, blue-green algae, etc. aren't substitutes! To get green algae growing, you'll need 2 Watts of light per gallon, at least. There needs to be a "turf" of green fuzzy algae on the plants and rocks. THAT'S what these little catfish eat." <Yep.> So, I got worried that, despite their healthy appearance, my little Otos weren't getting adequate nutrition. (I've attached a photo, in case you want to see how they look.) <If your Otocinclus have rounded bellies, then there's nothing to worry about.> I read online about how some people "farm" algae for their Otos, and I decided to try it. I went to a local Koi pond and took some rocks covered in thick green algae. I put them in a plastic tub outside, in direct sunlight, along with some pieces of driftwood from the pet store. My plan is to get the algae growing on the driftwood, and then to exchange pieces between the tub outside and my tank, to keep my Otos supplied with at least one piece of algae-covered driftwood at all times. (I will wait a full six weeks before putting any driftwood in the tank, as a safety precaution against any parasites that might have come from the pond. I'm guessing that after six weeks with no fish host, any parasites will have died.) <There's no need to quarantine bogwood or whatever left outdoors in water without fish. The main thing to take care is that excessive amounts of detritus don't get blown into the container. A few leaves won't matter either way, but anything that's been sprayed with pesticide for example would be potentially harmful.> But, now that I've got everything place, I'm having second thoughts, which is why I'd like your advice. I tried to identify my pond algae online, and it looks like what people call green "hair" algae, and most people who have it in their tanks seem pretty upset about it. Apparently, it can really take over. So, I'm feeling a little nervous about putting something in my tank that everyone else seems to want to eradicate. <You have a nice variety of algae there. The Moss Balls (actually algae) will collect bits of food and likely the Otocinclus will do some grazing on them quite happily.> Now I only have about .65 WPG on my tank, and as the quote above says, I need 2 WPG to grow the algae, so I'm hoping that it won't thrive once I bring it in. <The watts per gallon rule isn't hard-and-fast and does depend on various factors. In any case, take it for the guideline that it is, and if your Otocinclus are happy, that's all you need to worry about.> It only needs to stick around long enough for the Otos to eat it. I'm attaching a photo of the algae to this email. Can you tell me, what kind of algae is this? <Other than the Marimo Moss Balls, there seems to be some tufts of green algae on the bogwood.> Is it the kind that Otos need? <Yep.> And should I stick it in my tank? <Yep.> As always, thank you for your expert advice! Sincerely, Leah <Cheers, Neale.>

Re: Green algae for Otocinclus catfish  9/29/08 Hi Neale, Thanks for the info. Just one thing--you said, "Other than the Marimo Moss Balls, there seems to be some tufts of green algae on the bogwood." Those actually aren't Marimo Moss Balls. They're rocks covered in algae that I fished out of a Koi pond. <Ah, okay. All the same algae really, Cladophora (and related species).> The driftwood is from the pet store, and the algae that's growing on it is what has transferred over from the rocks. But as long as you still say this algae will be good for my Otos, then I'll put it in the tank. <It'll be good for them. Whether the algae will grow under poor light, I cannot be certain.> Thanks again, Leah <Cheers, Neale.>

Otocinclus; diet   7/29/08 Hey guys sorry to bug you but I have a quick question that your article on Otocinclus did not entirely answer. Well the back story is that I wanted some Oto's for my 20 gallon tank that I will be setting up in my dorm room next month and wanted to get Oto's that I knew were healthy instead of gambling on some new ones. I waited a week after the pet store I work at got the Oto's in (stupid manager pet my babies in with bumblebee catfish) to avoid the initial die off. Then I purchased 2 yesterday and put them on one side of a 10 gallon tank (at last check the pH was 6.4 and the tank is planted with Amazon sword, moneywort, cardinal plant, and water sprite cuttings I snuck home from work) with a divider that is keeping the Oto's, 4 feeder guppies, a black Veiltail angelfish which will join the Oto's in the 20 gallon, a pair of golden rams, and a third ram the male did not breed with from the other side of the tank that has ram eggs in it (the parents ate the eggs once and I wasn't risking it again {one day left!}). <Ah, potential problem here: Mikrogeophagus ramirezi need very warm water to do well, something between 27-30 degrees C; your Otocinclus on the other hand can't bear water that warm, and will be substantially more short lived. They want something between 22-25 degrees C. There's no happy medium here, which is why I consider Ram Cichlids as NON COMMUNITY fish, despite widely being sold as such (and why so many of them die after a few weeks from Hexamita and other opportunistic diseases).> The Oto's settled in nicely and cleaned a 5 in piece of slate in a day. My question is about what to feed them when the algae runs low. You mentioned lettuce and peas, but is boiled cucumber fine? <Cucumber is NOT fine... it's mostly water. (To quote the immortal Samuel Johnson, a "cucumber should be well sliced, and dressed with pepper and vinegar, and then thrown out".> The Oto's are eating it right now and I was just wondering if it was healthy/ nutritious enough. <Your best bet is standard issue algae wafers, of the type sold for Plecs. These should make an adequate staple. I'm also a fan of offering Sushi Nori to herbivorous fish. You can buy this stuff from Asian supermarkets very inexpensively (here in England, it's under £1 for 10 sheets). Attach strips of the stuff to a lettuce clip and let your catfish graze. These two foods could be alternated through the week and should keep your Otocinclus in tip-top condition.> Thanks again. <Cheers, Neale.> Re: Otocinclus; diet  7/29/08 I do believe that my water is not really too warm as it is a 5 gallon heater set at max. <It's not a question of belief. If the water is above 25C/77F, the Otocinclus *will* be heat stressed, and long term won't thrive and likely die prematurely. If the water is below 28C/82F the Mikrogeophagus ramirezi will be too cold. Their immune system will be weakened, and sooner or later they will contract an opportunistic infection and die. These two species live in completely different habitats. The Mikrogeophagus ramirezi inhabit thickly vegetated, sun-baked pools, whereas Otocinclus inhabit sandy or muddy fast-flowing streams.> And I will be moving 2 rams to the other side of the divider as all the eggs were lost to fungus/ infertilization (tear). <High temperature (28-30C) is essential for successful Mikrogeophagus ramirezi reproduction, as is very soft (<5 degrees dH), very acidic (pH 5-6) water. Outside of these environmental conditions, you will see precisely what happened here: infertile eggs, or even if the eggs by some miracle do get fertilised, the parents fail to brood them properly or the fry cannot hatch out. In any case, unless you picked up your fish wild caught or from a specialist breeder, don't get your hopes up too high. The quality of the "mass produced" Ram Cichlids is appallingly low. Fertility is low, and much of the colour you see is artificially induced using hormones and additives to their food. They also seem to be tanked up on antibiotics, and quickly weaken once they leave the fish farm. I hate to be a downer about these beautiful fish, but I simply don't recommend people keep them anymore. Much better is Mikrogeophagus altispinosa, a much easier to keep species sold as the Bolivian Ram.> I will also make sure I pick the wafers up tomorrow at work. Thanks <Cheers, Neale.>

You Say Po-toh-to, I Say Po-t-otto
Do Otocinclus cats eat dark green Cyanobacteria in a FW tank?
<Possibly, but are you sure you're dealing with Cyano?  It most certainly does happen in FW tanks, but plain ol' green algae is a likelier bet - and the Otos would most definitely chow down on that.  The best way to fight Cyano in a freshwater tank is to get some vascular plants to out-compete it; basically, the plants are more efficient, so they suck up nutrients before the algae can, so the algae misses out and dies off.  Myriophyllum, Anacharis/elodea, hornwort, or even a couple floating water lettuce would certainly help you in this battle.>
Also what is the proper pronunciation of Otocinclus?  Like Otto-sin-klus or oh-to-sin-klus?
<planetcatfish.com says "auto SINK luss".>
Thanks!
<Sure thing!  -Sabrina>

Otocinclus Meals
Robert,
<Hi, EJ, Sabrina here tonight, instead>
I read your article on Otocinclus on wetwebmedia.com. Thanks.
<Glad you enjoyed it!  I'm sure Bob appreciates the thank you greatly.>
A couple questions:  In your article, you mentioned that they need wood to survive.  What kinds of North American woods are acceptable for Otocinclus?  
<Pretty much anything that's been *very* well cleaned and either sinks on its own or is weighted will do.  Check out your LFS for driftwood ideas.>
What state should the wood be in?  Fresh, weathered, decomposing, etc.?  
<Very well weathered - as in, no bark remaining whatsoever.  Wood that is decomposing poses a problem as it will decay in the tank and make a genuine mess of things.>
What is a good brand of sinking pellets to feed them?  
<Frankly, my personal favorite dry food brand is Hikari, but I rarely (if ever) use algae wafers to feed my algae munchin' dudes.  Algae based frozen foods (Ocean Nutrition's Formula Two, for one example) are a good prepared food item to offer.>
Will they feed on other vegetables besides the spinach, Nori, and peas you  mentioned?
<Blanched cucumber and/or zucchini, perhaps the soft insides of green beans.... some years back, my Loricariids always appreciated the asparagus that I refused to eat as a kid....>
Thank you very much.
<You bet.  Wishing you well,  -Sabrina>
EJ

Getting food to the Corys and the Oto   2/22/06
Hello WWM crew,
I have searched your site and I think the single tiny wiggly white worm I just saw in my tank is Planaria.  It is a very very fine threadlike white worm of about 5mm length. I probably only saw it because I was sitting very close to the tank.
Am I right in understanding these are from too much waste product and uneaten food?
<Yes.>
Do you have any delivery tips for the food?  I was afraid if I hid it the Oto and Corys would not find it either.
I have a bit of driftwood with a plant on it that I can put food under but it seems nearly all the fish can wiggle in there to get it!
I thought my tank was very very clean.  I change 25-30% of the water once a week with another bucketful or two changed halfway through the week as I don't like to see the Corys searching around for food in droppings. Yuk.
I vacuum the open area of gravel once a week and stir up the other areas with the siphon hose as the vacuum wont fit amongst the plants.  I have quite a lot of live plants.
My problem I guess is I have been overfeeding although everything gets eaten quickly.
<I agree.  Your vacuuming technique sound very thorough.>
I am always worried about getting enough to the Corys and the Otocinclus.  The other fish are total pigs and tend to eat everything.
I feed a couple of pinches of flakes
<Try backing off a bit.  Try to lure those speedy Tetras away by sprinkling a bit on one side of the tank, and then sprinkling the rest far away from them.>
, two sinking Cory-food pellets
<Feed just one pellet.  Break it up into a couple pieces, always drop it in the same place in the tank every day, so the Corys get into a pattern/know where to find it.  Feed the Corys about 1/2 an hour after you turn off the light tank light.>  
and a half of an algae wafer once a day with a day of no food now and then.
<Leave the wafer as a treat for every now and then.>
Also feed a frozen bloodworm cube once a week and some cucumber every few days (the Oto loves that).
<OK as long as you are subbing this for the other foods you described.>
I have a 26 gallon freshwater tropical tank (AquaOne 620) with a filter and lights built into the hood
Temperature about 78 degrees.
Ammonia and Nitrites are zero.
Tank has been set up for 10 weeks and is fully cycled.
The tank is stocked with:
I angelfish
3 black skirt tetras
5 Corydoras
2 dwarf Gouramis
1 Otocinclus
<A bit heavily stocked for that size.  Probably contributing to the waste/food levels for Planaria and algae.  Your Angel will get quite large, produce even more waste.>
I tried leaving the lights on a bit longer to grow some algae for the Oto...but instead of the brown algae I once had green algae has grown on some of the Anubias and Oto doesn't seem to make much difference. So that might have been a mistake? Do you think if I revert to my original 8 hours of light the Oto will eventually eat it all?
<Go back to 8 hours.>
Or maybe should I get an additional Oto?
<Otos do prefer the company of their own kind, but you are already heavily stocked.>
So much to learn.  Any advice you can give would be very much appreciated.
Many thanks,
Gillian  : )
<Jason N.>
PS I think your site is terrific, you folk obviously love what you do although I expect if you get many more "My Betta sits at the bottom of his bowl" questions you might implode.
<Thank you!>

Re: Getting food to the Corys and the Oto   2/22/06
Thank you Jason for your speedy response,
I was very disappointed when I did my own sums and realized "no more fish for me"....well, in this tank anyway.  Everyone laughs when I talk about my next tank.
<You've been bitten by the bug.  God have mercy on your pocketbook.>
This one is a practice to see if I can keep up the enthusiasm before going mental on a giant tank.
<I find that my largest tanks are the easiest to care for.  It is far harder to make most mistakes in 50+ gallons of water.>
You know what?  I think I can!
<Glad to hear it!  Now there is only the problem of what you're going to do with your current tank when you get a new one...>
Thanks again from Australia,
Gillian  : )
<Jason N.>
 

Question for Neale about TFH article, 10 gal. stkg.  Otos f'    01/13/2008 Neale, <Hello Evan,> I read your article in the TFH about 10 Gallon stocking. I was wondering if you had a reason for not mentioning Otocinclus along with the Corydoras. Is there a specific reason to not add the Otos to a 10G tank or were you just limiting yourself to keep the article concise? <Yes, there was a specific reason for leaving them off: Otocinclus spp. have an abysmal track record in aquaria generally, the VAST majority dying within a few months of introduction. I would never recommend them to anyone without several years of experience, and even then, only when placed in a mature tank (lots of green algae/aufwuchs) and excellent filtration. This pretty much rules out the average 10 gallon tank received as Christmas present, which was the focus of the article. If you want an algae-eater, get cherry shrimps; if you want a catfish, get Corydoras hastatus or some other Dwarf Corydoras. Both these will prosper without anything more than an "average" level of care, i.e., water changes, proper food, etc.> I ask because I have a 10G with 9 Glowlight Tetras to which I would like to add 3 or 4 Otos (as soon as LFS orders some). <Think very carefully about this, and only if you have LOTS of green algae. Otocinclus really don't eat anything much besides green algae and the microorganisms therein. Brown algae, blue-green algae, etc. aren't substitutes! To get green algae growing, you'll need 2 Watts of light per gallon, at least. There needs to be a "turf" of green fuzzy algae on the plants and rocks. THAT'S what these little catfish eat. On top of that, you need plenty of water flow (at least 4x the volume of the tank in turnover per hour, and ideally 6+) and above-average oxygenation. Nitrates need to be close to zero, and certainly less than 20 mg/l. If you can't answer all these demands, then skip Otocinclus.> I perform 40% WC every 5 days, so I think I would be able to keep that many fish and maintain good water quality. What are your thoughts? <Best avoided, frankly.> Thank you, Evan <Cheers, Neale.> Re: Question for Neale about TFH article plus Corydoras  1/14/08 Dr. Neale, <Evan,> Thank you for your responses to my questions about Otocinclus. Through my web-based research I thought that supplementing the Otos' diet with Nori and vegetables would be adequate, so I'm very grateful for your input on the matter. <You may be fine doing precisely that, but the cold, hard reality of the matter is that whatever people do, most Otocinclus don't seem to survive long in anything other than a big, mature tank with plenty of algae. Their diet is a subject of some discussion among hobbyists. They may be partly parasitic as well as algae-eaters: in aquaria they have been reported MANY times to eat the mucous and skin from large, slow fish. I have seen this myself, my Otocinclus causing a significant amount of damage to the body of an Awaous goby. Do they eat mucous only when hungry? Is it something they do regardless? No-one really knows.> On the subject of the Corydoras hastatus & C. pygmaeus: I currently have medium to large "aquarium gravel" (colored pebbles) up to about 1cm in diameter. Would this substrate be acceptable for keeping either of the above Corydoras species? <Acceptable yes, ideal no. With all Corydoras, the best results come with lime-free sand, simply because it's more fun to watch them plough through the stuff. That said, the midwater Corydoras species like Corydoras hastatus likely don't care either way.> If not, what kind of substrate do you recommend? <The best for a small, planted tank is unquestionably black sand. Looks lovely, and because it removes upwelling light, fish adopt their brightest colouration.> If I need to replace the gravel, what is the best method? <If you have an undergravel filter in your tank, best not to change the gravel at all. But if the gravel is purely decorative, there's no real problems. Just take all the fish out, put them in a tub or bucket with the filter connected to that vessel so the bacteria stay happy. Then empty out the aquarium, remove some or all of the gravel, and then add the cleaned sand to a depth adequate for the plants. If no plants (or at least no plants with roots, as opposed to epiphytes) then you only need 2 cm/1 inch of sand.> Again, thank you for your help. Evan <Happy to help, Neale.>

Oto loses colour Hi, We have a sick Oto which has suddenly lost its pigmentation and is looking a sickly grey. It is swims weakly, sometimes floating at the surface and drifting in the current. Otherwise its body, fins, etc. look in good condition. Can you suggest any remedy or is this something to do with the tank conditions? We have a 180-litre (40 gallon) community tank with 9 guppies, 3 minnows, a Pleco and 5 Otos altogether. It has some live and plastic plants, a couple of logs and a small rock pile (slate), i.e. there is a relatively large surface area available for the Otos to graze on. It has been set up for about 3 months, but, about 3 weeks ago, we had problems with water quality, fungus and white spot. These were successfully treated with 10% water changes every day and ESHA 2000 and EXIT. Treatment finished 7 days ago. Current conditions pH = 7.8, KH = 6°, GH = 12°. Ammonia, nitrite and nitrate levels all low. We have isolated the sick Oto. Grateful for your advice. Regards, Quentin <Hello Quentin. Let me start by making a general statement about Otocinclus: they are extremely difficult to maintain, and the vast majority die soon after import. The problem is that they feed on really only a single thing -- aufwuchs, a combination of green (and exclusively green!) algae together with the tiny invertebrates that live within that green algae 'biofilm'. Unless you have an established aquarium of large size with very strong lighting (2+ watts per gallon) so that green algae can flourish, it is exceedingly unlikely your Otocinclus will be getting enough to eat. How many months it is before they die is variable, but starve they will unless ample substitutes are provided. Algae wafers can work, but Otocinclus find it difficult to compete with other fish, and the fact you have other algae-eaters, specifically guppies and Plecs, makes this point critical. For this reason, I simply don't recommend them as community fish. Furthermore, while water chemistry itself isn't all that important, temperature and water quality are very important. Most people keep their tanks far too warm for Otocinclus, which come from cool, fast-flowing streams and want something in the 20-25 degrees C range rather than the usual 24-28 degrees C most people maintain standard community tropicals at. In other words, a near-subtropical, fast-water tank with things like White Cloud Mountain Minnows and Danios is much closer to what they want than a standard Amazon community aquarium. You also mention ammonia and nitrite levels as being "low" -- but be under no illusions here, Otocinclus MUST have zero levels of both. If you can detect either in your tank, it is simply not suitable for Otocinclus. In all likelihood the sickly specimen will be dead within a few days, so treatment here is irrelevant. Optimizing water quality, lowering water temperature, providing ample green algae and suitable invertebrates would all be things you could do to help the isolated fish, but that's about it. For the rest, you need to ensure your aquarium satisfies the demands outlined above. Hope this helps, Neale.> Re: Oto loses colour 7/6/08 Neale, Many thanks for your helpful advice. The Oto has now died, sadly. However, we will develop the tank environment to make it better suited to Otocinclus. They are an entertaining fish to watch. <Yes they are. In the right tank, they can be great fun. In the wrong tank though... My most recent run-in with this species was a disaster, some of the Otocinclus deciding to graze on the mucous of some large benthic gobies. They have a reputation for attacking big, slow moving fish such as Discus and Angelfish. On the other hand, aquarists like Takashi Amano make much use of Otocinclus in planted aquaria, usually alongside Caridina shrimps as a superb combination for green algae control in brightly lit aquaria.> Thanks again. Your website is a mine of information and a great support to the budding enthusiasts in our family. Regards, Quentin <We're happy to help, and thanks for the kind words. Cheers, Neale.>