Sre corys necessary?

[Katy1956]

My LFS always says I need at least 6 corys for bottom feeders for my 29 gal FW tank. Is this true? Do all FW tanks need corys for keeping the bottom right? I have had 2 batches of albino corys and cannot keep them alive. They are so fun to watch, but they don't survive. I now have 3 green corys and the LFS said I need 3 more. I love to watch all the corys as they are so playful, but I have bad luck with them. All my other fish do fine in my tank. My parameters are good, I change the water every week or so (my LFS said I do too often water changes :confused: ), and have garnered alot of info and help from this forum. Thanks! Katy

[dorkfish]

Having 0 or 6 or more corys is really what you should do as they are schooling fish, but in my expierience they do OK in groups of three. In response to the thread title, no, corys are not nessisary.

Your LFs is wrong about weekly water changes being too much. The truth is, as long as your tank hasn't gone into old tank syndrom (high nitrates and fish dyding after being in your tank for a long time are two of the symptoms), you can never do to many or too big a water change.

Also, if your LFS told you you had to have corys, or they pressured you into buying corys or any other fish, stop going there. No good ever comes from an LFS pressuring you into buying something in my expierience.

[boofish2]

I've been having a hard time keeping corys as well! I've had a couple of batches of pandas and am down to 4 from 9. It is true that they are a bit more active in larger groups but my current school of 4 seem pretty content. As far as being necessary, corys should not be used as a replacement to doing gravel vacs. but I'm sure they make some difference in the cleanliness of the tank.
BTW - my pet store guy said not to do too many water changes either b/c of disruption to your biological filter although he did say 1-2 times a week is okay.
I usually do a 20-25% water change twice a week.

[dorkfish]

BTW - my pet store guy said not to do too many water changes either b/c of disruption to your biological filter although he did say 1-2 times a week is okay.
I usually do a 20-25% water change twice a week.

There is no bacteria in the water; all the bacteria is on the tank walls, filter media, decor and gravel.

[thesydmonster]

You do not HAVE to have cories. They do well in groups of their own kind. If you have 3 doing well together, keep it at 3 :) Don't ever feel pressured to get more fish.