foggy water

I have a 10 gallon tank. I have a biowheel filter system. My tank was
having an algae issue for some time which water changes wouldn't fix. The
stones were several years old so I thought perhaps this was the issue. I
changed the stones yesterday, and took out three gallons of water as well.
The water now 24 hours later looks clean but there is a fog look to it. The
smaller fish (tetras, catfish) are acting fine. The large angelfish while
swimming around and acknowledging me when I walk into the room, will not eat
and is hanging around the top of the water quite a bit (though not gasping
at the surface). What could be the issue with the foggy water? Is the
angel probably just stressed some? I will do a test on some of the water
parameters and post them separately.

water parameters a
Ammonia 0 ppm (no surprise there since the tank is so clean, new stones,
etc)
Nitrite 0 ppm
GH & KH rnage 50 ppm
pH is high at about 7.6 (usually it is 7.0)

Could this pH spike be causing the foggy water and the angel's stress?
Will the tank cycling with the bio filter fix this on it's own?

"Tynk" wrote in message
What's your normal water change and gravel vacuuming schedule?

Just once every 3 weeks, always been that way with no issues until recently.

How long has the tank been up and running with fish?

6-1/2 to 7 years.

You also didn't mention the amount of tank mates.

One large angel, two small cory cats and two tetras.

Algae problems can occur from not enough water changes, over feeding
issues, over stocking, or direct sunlight.

I don't believe I over feed, everything is eaten, doesn't appear I overstock
and there is no sunlight as the tank is in the basement. I felt that the
stones were the issue. While I siphoned the stones they still seemed to
hold a lot of matter in them, as evidenced when I took the stones out to
replace them. The same stones have been in for the life of the tank (nearly
7 years). They also were not typical gravel stones, but recycled polished
glass. I only do water changes about every three weeks, as I have done for
as long as I've had the tank. When I did my usual water changes every three
weeks, I would take out three gallons (via gravel siphon) from the 10 gallon
tank. This always worked well for years with great water until the last few
months when an algae appeared (blanket algae easily removed from the
stones). I was hoping the changing of the stones to new gravel and a good
algae spot cleaning would do the trick, I guess with that matter time will
tell. As for the cloudy/foggy water issue right now, I did leave the old
filter in the biowheel filter, as well as still keeping six gallons of the
original water. So I am a little surprised for the bacteria bloom you
mentioned but I don't doubt your suggestion that it is probably the cause.

"Tynk"... I guess unfortunately, I have always replaced the biofilters
(every 3-4 weeks). I had never heard of rinsing them in old tank water.
The tank is slowly starting to uncloud now. The tetras I have are gold xray
tetras. I had 5 of them going back to three years or so ago, slowly they
died off, usually from the body curving (not sure what causes this) or by
getting something similar to a dementia (can't swim straight or at all
anymore). So right now I have two left. Then along with the angel and two
corycats, its a nice peaceful tank, I feel plenty of room for the angel but
I'm no expert. The angel's body is about 3" diameter. Here is a photo I
just took of the angel this evening (photo came through nicely through the
"cloudy water"). He/she is going on three years old now. Very pretty
coloring, lots of personality (some people think it is nuts to say a fish
has personality or recognizes you).

http://www.knack.com/angel.jpg

Thanks for all the info and conversation Tynk. Some years ago I tried my
hand at pairing up mates and went so far as them laying a couple sets of
eggs on a piece of slate. After they were layed I put plants around it to
protect them from the parents eating them. I had an air stone placed to
give a gentle air circulation and the eggs died both times. I really tried
to sex the angels, read a bit on it, heard it was hard to accurately do. I
believe I had two females, even though one acted as the male in
"fertilizing" the eggs after they were laid. I didn't get the result I
wanted, but it was facinating to watch.

Do you find that the mates eventully turn on each other? Always happened
with mine. They would get along great for a long time having grown up
together, "mated" and then eventually they would fight horribly. Now I just
keep on angel in the tank.

By the way, water is now nice and clear. Everyone is acting normal again,
eating normal. However I just noticed on one of the angels side fins there
are some white spots (like ick spots). Should I be concerned? Is waiting
until Saturday to do a water change okay? 2 gallons from the 10 gal tank?
Right now the parameters are good.