Hey Mr. Otto.. eat something already!

[Samala]

Ok here's the scoop: I have my twenty long setup with 40W 6500K, CO2 at 15ppm, additions of KNO3 and pmdd for traces and have been monitoring the crap outta the tank the past three months basically. In that time I've had wisteria take off, sag subulata is doing well now, Vallisneria practically took over and had to be traded away, and now Ludwigia is coming along nicely.

But for all this time I've had this lovely growth of brown algae that sticks around and refuses to die a lonely strangled death from lack of nutrients! Grrr. I'm pretty sure its diatoms of some variety, its the lovely filmy brown stuff. Green spot algae will show up every once in a while too.

So I chang 20% water every week and dose fertilizers accordingly, nitrates never read over 5ppm. Beyond upgrading lights (which I think I will anyway) I figured, hey, lets get some Ottos for this tank and see if that works, seeing as how everyone loves them.

Welp, three days ago I went out and got three of them for the 20long and fretted all afternoon about whether Mom and Dad kribensis would beat them up - the fry are about 1/2-3/4" now. No attacks on the ottos.. but they havent even made a dent in the algae. They just hang out all day practically motionless.

I was quite careful with acclimation and these looked fantastic at the shop - they were in a large planted tank happily munching away at some green haze on the glass. Maybe they dont like brown veggies?

Any suggestions anyone? Or just not freak out and leave the fish to do their thing? Thanks!

>Sarah

 

[beviking]

They sure can be finicky! You aren't supplimenting them with anything are you? If they start to look too gaunt, give 'em something a couple times a week just so they don't starve. Other than that, I'd say wait. They should get hungry enough and eat the brown stuff in between the LITTLE you give them to keep them alove. If not, you might try buying hungrier looking ottos next time, j/k!

 

[Kissofthegorami]

Try more water changes. Otos are picky, often u get several different kinds at a given LFS and they have different preferences. I find it best to mix my algae-eating species. I use otos, neritina snails, and amano shrimp.

 

[Aqualung]

Give them time, I'm sure they are eating the diatoms as that's normally their favorite type of "algae" (not truly an algae). Diatoms IME will normally go away as the tank matures, too - so just be patient.

 

[jonathan03]

The ottos I have had never ate the green spot algae off the glass. You'll have to clean that off yourself. They usually do go for the brown algae though. Brown algae is very vague though. There are lots of varieties that look the same and ottos are pickey.

You might just have skitish ottos. They are some that only come out when you turn the lights off.

Do you have a low ph? Ottos like a ph of 7 or a little less.

I would try giving them some other type of food to keep them healthy. Maybe a small peice of cucumber or zuchini.

Maybe you can try a few snails if you don't mind them.

 

[Samala]

Thanks everyone for the help - I did start giving the ottos a teeny tiny bit of zucchini to be sure they are eating something. They have started in on the brown algae and the tank is starting to look really good. And you're right, they havent gotten close to the green spot, but that's really easy to take off the glass with a filter pad.

Jonathan - my pH is about 6.6 so I think those ottos should be happy with water quality. I know 'brown algae' diagnosis is quite vague but I'm about 100% sure its a variety of diatoms. I was wondering if it was some kind of beard algae for awhile but its a film, no threads or discernable structure to it. Comes right off if I wipe it with my fingers.

I really thought it would be gone by now, the tank is just over three months. Oh well, I've got lots of patience (my saving grace in this stinkin hobby somedays! )

Again, thanks for the help guys!
>Sarah