Unlucky With Oto's

[jrussuk]

Can anyone give me advise on keeping otos, I really like these fish but never have any luck keeping them. i have originally bought 4 but after a period of a month three died i bought another 2 which lasted about 6 months and died leaving the original one still looking healthy. all my tank stats are fine (ammonia and nitrites 0, nitrate about 20, ph 7.1 tem 24). The thing my wife noticed was they seem to die after my weekly water change. I use delorinater try to match the tempteture of the new water etc. so im not sure what i might be doing wrong. They are kept in a community tank (90Ltr) with peaceful fish and are never bullied.
Any advise would be appreciated as i'd like to perservere with them before looking at another small alge eater (pitbull plec??)

Many Thanks

 

[nmonks]

Otocinclus are difficult to keep. They need cool, well oxygenated water with lots of water movement. They inhabit shallow streams and just don't do well in the sluggish water in the average community tank. They are also aufwuchs feeders, and feed on green algae plus various small invertebrates. They don't eat diatoms or any other type of algae.

In practical terms, you're looking at a cool (22-24 degrees C) aquarium that already has lots and lots of green algae already growing. To get green algae you need a LOT of light, upwards of 2 watts per gallon. You need to be using a strong power filter that gives not less than 6 times the volume of the tank in turnover per hour, and ideally 10 times.

Water chemistry isn't critical, but avoid very hard/basic.

Keep in schools of at least six, ideally 12 specimens.

Supplement the algae with bloodworms and algae wafers. Do not add ANY other algae eaters or bottom feeders. NONE!!!

Keep away from slow-moving or disc-shaped fish (such as Angels) -- these fish are known mucous-eaters that will parasitise any fish that can latch onto.

Cheers, Neale

 

[Ian H]

Otocinclus are difficult to keep. They need cool, well oxygenated water with lots of water movement. They inhabit shallow streams and just don't do well in the sluggish water in the average community tank. They are also aufwuchs feeders, and feed on green algae plus various small invertebrates. They don't eat diatoms or any other type of algae.

In practical terms, you're looking at a cool (22-24 degrees C) aquarium that already has lots and lots of green algae already growing. To get green algae you need a LOT of light, upwards of 2 watts per gallon. You need to be using a strong power filter that gives not less than 6 times the volume of the tank in turnover per hour, and ideally 10 times.

Water chemistry isn't critical, but avoid very hard/basic.

Keep in schools of at least six, ideally 12 specimens.

Supplement the algae with bloodworms and algae wafers. Do not add ANY other algae eaters or bottom feeders. NONE!!!

Keep away from slow-moving or disc-shaped fish (such as Angels) -- these fish are known mucous-eaters that will parasitise any fish that can latch onto.

Cheers, Neale

Are you kidding? they LOVE diatoms!!! Also i have them in my community planted tank, warm water (around 26 - 28 i think) not really fast flowing (worked out at around 5x i think) water along with 5 plecs (9 including the babies) and 4 cories and they are doing fine!

Also to get green algae you dont need alot of light, just dont have plants taking in the light/nutrients and you will get algae.

Alot of people say they are hard to keep, but i think they just need a mature aquarium to be honest

 

[nmonks]

Are you kidding? they LOVE diatoms!!!

They may eat them, but I'm not sure they digest them, or can live off them. Perhaps they can, I just don't know. In the wild they're "aufwuchs" feeders, which means green algae + microorganisms.

Also i have them in my community planted tank, warm water (around 26 - 28 i think)...

In the wild they experience 20-25 degree C water. See Fishbase. No real reason to keep them any warmer, and since warm water contains less oxygen, long term isn't a good idea.

...not really fast flowing (worked out at around 5x i think) water along with 5 plecs (9 including the babies) and 4 cories and they are doing fine!

So far they're doing fine, at least. But you may have a nice little tank where they're happy. Maybe you're a really good fishkeeper with a knack for keeping tricky beasts alive. But as a rule, these fish have horribly high levels of mortality in standard aquaria, as this original posting makes clear. As ever "your mileage may vary", but if you want to maximise the chances of success, you need to keep them cool, in a tank where they don't have to compete for algae, and where they can snack on bloodworms and the like without competition. My advice comes from this perspective: what's been tried and tested. Think Delia Smith rather than Anton Mosimann!

Also to get green algae you dont need alot of light, just dont have plants taking in the light/nutrients and you will get algae.

Yes, you get lots of algae in a tank without plants, but mostly diatoms and perhaps red algae. Green algae needs strong light to thrive. Anyone can test this: stick some rocks in a tank with 1 Watt per gallon water and those rocks will get covered with brown slime, diatoms. Double or treble the lighting and the rocks will go green, Chlorophyta.

Alot of people say they are hard to keep, but i think they just need a mature aquarium to be honest

I actually do agree 100% with this, that in the right aquarium they aren't especially delicate, and one of the keys to success is that the tank is mature. If you "break the rules" about temperature and tankmates, then I dare say a mature aquarium with lots of stuff for them to eat is perhaps adequate even if not ideal (in my narrow sense). The problems come where people throw Otocinclus into a new community tank assuming they'll be as easy to keep as plecs or bristlenose cats.

Cheers, Neale