what the hell happened

[optix]

I've had a 20 gallon tank raising two two inch juvi oscars until they are 5 inch's before I place them in the 150 with my jack dempsey, well everything was fine, they never fight and still don't, but I changed the filter to a penguin biowheel and all hell has broken loose, I have white worms growing and crawling on my glass, algae just went berserk and is masssssivly growing on my slate rock, and the water is really cloudy, and all of a sudden my smallest red has hole in the head. what in the hell just happened here. Any info would be appreciated, btw, I do 25% water change every week, so its not and water changing problems going on here

 

[heat]

It's possible that when you removed the established filter, unless you reused the media, that you threw your tank into another "cycle" of sorts.

Have you tested your tanks water since you changed the filter?

 

[NJ Devils Fan]

Yea, what are you water parameters?

 

[Marcus]

I agree with the 'throwing the tank into a new cycle' theory.

As far as the worms are concerned, it is simply a sign that the gravel is in need of a VERY thorough cleaning. They are not harmful and simply live off of the waste and detritus in the gravel. You'll probably notice that the majority of them are on the glass either just above or just below the gravel line.

At this point I'd perform a gravel vac and change 50% of the water. Then, keep a very close eye on the ammonia and nitite levels. 2 4"-5" oscars in a 20 is really pushing the envelope. With that kind of a load I would have opted for a bigger filter like the Penguin 330!