I have a pair of three-stripe corydoras in my 36G tank. They are always very busy and active. I noticed one perched up in my water wisteria a couple nights ago, and when I looked closely, I realized his whiskers were gone! I looked for the other one...same thing. Everytime something looks off I test the water - water is all good according to the master kit. Hubby and I looked online and found this could be due to them being picked on (I have not SEEN anything bothering them), rough gravel (I do have gravel in the tank and I have seen them doing a face dance often on a very ... knobbly bit of decor), or bacteria in the gravel. I do not vacuum often because there are a lot of live plants in the tank.
So here's where the questions start!
Should I be vacuuming a tank with a lot of plants? If so, any tips on not damaging the plants too much?
I put the cories in my floating breeder box so they can heal up. They seem to be doing fine so far. Since I'm not sure what in the big tank led to this, I'm wondering - would they would fare better in the divided 6.6G I keep for Redfish and Ghost, since it has a sand bottom? Would a 6.6 be workable for two small cories and 2 bettas? (6.6 is a filtered tank)
Another option is to do a sand bottom on the 5G tank I have not yet set up for Shimmer, my sorority girl who got sick and was injured during the setup phase. Would a 5G be OK for 1 betta girl and 2 small cories? It would be filtered.
My last option would be to just release them back into the big tank (after removing the particularly knobbly cave) and keep a close eye on them.
I feel bad for my poor cories