I turned the air pump back on. The gang value to the airstones does not
adjust well, they are either on or off. so I can't slow the air bubbles.
Would a power head agitate the surface less than the air stone. If so would
I need a power head for each riser? If I use one power head what stops
water from being draw down the other riser rather than through the gravel?

"rnj" wrote in message
...
Leaving the UGF in the tank without circulation causes a void where
anaerobic (swamp gas) conditions can occur. Your fish are starting to
suffer
from Nitrite and ammonia that is slowly diffusing though the gravel.
Gasping
is a sign of stress that can be caused by lack of oxygen, chlorine,
ammonia,
nitrite, high or low pH, and disease. If you're not going to use the UGF,
take it out. One of the reasons that plants don't due well with them is
that
the roots like to be covered with gravel. That empty void stops the roots
from growing properly.


"Scott Rogahn" wrote in message
...
Two days ago I started injecting CO2 using the Hagen natural plant
system.
To avoid loss of CO2 I turned off the air driven under gravel filters.
UGFs
seem to be frowned upon for planted tanks anyway. The surface is still
agitated by the Millennium 2000 hang on back type filter. This filter
takes
in air at the impeller and bubbles it across a grid before the filter
pad
which they call at wet/dry filter. Other than that no air has bubbled
though this tank. The filter is set to low to further minimize surface
agitation.

This morning I looked at the fish before the lights turned on. The
zebra
danios and the golden clouds were all swimming about 1 inch from the
water
surface. They did not seem to be in distress as best as I could tell in
dark. These fish do not normally stay at the surface during the day so
this
is different behavior.

The clown loaches, SAEs and ottos were much deeper in the water and
appeared
normal.

Is this gasping or some other sign of low oxygen?

My PH has dropped from off the scale (I am using the test kit for my
pool,
Max is 8.0) to 8.0, so I believe the CO2 injection is working. I can
see
the bubbles get smaller as they travel though the diffuser, which also
tells
me the CO2 is dissolving in the water. I don't know actual levels. The
Red
Sea Plant Care Mini Lab test kit is about worthless. I tried to measure
CO2
before injecting. The test indicated more than 20ppm. What is a good
test
kit For Kh, PH and CO2? The Red Sea kit does not measure PH and Kh like
I
thought it would but rather a single test which reads CO2 directly. If
it
worked witch it doesn't

I do know the total alkalinity of my tap water is very high. I need to
a
lot of Muriatic acid to my pool at the start of each season. Muratic
acid
seems strong to add to the fish. So I haven't. Aquarium PH down does
nothing however.