oops guess I left out some important info
some new rocks, new driftwood, and new substrate (taking gravel out putting sand in) I am doing it gradually.
pH = 7.0 ammonia = undetectable nitrites = undetectable nitrates = unknown
= 10 degrees
Right now I have 4 harlequin rasboras. Only 2 tiger barbs (had six but quite a few from one batch got odd mouth deformities - seemed to be congenital); I will be getting rid of them soon but I am quite sure they are not picking on the otos. 6 otos, 1 mosquito fish.
75 gallon tank - only filled to 60 gallons 6 sided so deep
I did a water change of about 40% a week ago (normally I only change water about every 2 months because it just seems to really upset my fish - I don't seem to get waste buildup with the plants & I do have DIY CO2
& plants are fertilized) but I have disturbed the substrate so there is still some turbidity & I will have to vacuum again when I am done with renovations. I thought about taking all the fish out but when I have done this in the past they seem more stressed (i.e. lack of color, refusal to eat, odd behavior) than when I leave them in & make gradual changes.
I don't remember the name of my filter but its a hang on the back (though I don't use it that way. I set it on the tower of driftwood & rocks in one corner. I think it does about 50 gph
I think thats it. Oh tank has been up for over a year.