I have a 75 gallon tank with about fifteen rainbow fish. I've ordered
CO2 equipment which should arrive this week.

What's the best way to start this up? Do I just run it for brief
periods of time at first, like an hour a day, and gradually build it
up? I don't want to make any massive changes in the tank chemistry at
one fell swoop.

The pressure gauge I got has a solenoid, so I was planning to run on a
timer with the light hood, so the CO2 unit will ultimately be on for
about 9 - 10 hours per day. Mostly, I just don't want to come down
after the first day to discover 15 dead rainbow fish.

Currently, the tank contains several java ferns, two sword plants, a
micro sword, and an anubias.

Any tips from you pros would be appreciated,
Andy

ah wrote:

I have a 75 gallon tank with about fifteen rainbow fish. I've ordered
CO2 equipment which should arrive this week.

What's the best way to start this up? Do I just run it for brief
periods of time at first, like an hour a day, and gradually build it
up? I don't want to make any massive changes in the tank chemistry at
one fell swoop.

The best way to build up is to start with a low constant bubble rate.
Start with one bubble per second. Wait a couple of days, then check the
pH to see how much CO2 is being dissolved. Gradually increase the bubble
rate over the course of a week until your preferred pH has been
achieved. Check that once you've set a bubble rate it stays put and
doesn't wander. I have a cheap regulator that changes CO2 flow depending
on ambient temperature (not good). I use a pH controller to overcome that.

The pressure gauge I got has a solenoid, so I was planning to run on a
timer with the light hood, so the CO2 unit will ultimately be on for
about 9 - 10 hours per day.

I use a solenoid linked into the lighting timer on my 16 gallon tank. I
have it on 12 hours per day. When the lights go off, the CO2 flow is
stopped. I don't find that the pH changes much over the course of the
night as the plants start expiring CO2 anyway. I have the bubble rate on
this tank set to 1 every 3 seconds. It's only 16 gallons so it doesn't
require much CO2. My 75 gallon requires at least 2 bubbles per second.

Mostly, I just don't want to come down
after the first day to discover 15 dead rainbow fish.

Start with a constant, low bubble rate and don't let anything or anyone
modify the setting accidentally.

Currently, the tank contains several java ferns, two sword plants, a
micro sword, and an anubias.

My java ferns are always covered in small bubbles of oxygen. How many
watts of lighting do you have there?

Nikki

ah wrote:

I have a 75 gallon tank with about fifteen rainbow fish. I've ordered
CO2 equipment which should arrive this week.

What's the best way to start this up? Do I just run it for brief
periods of time at first, like an hour a day, and gradually build it
up? I don't want to make any massive changes in the tank chemistry at
one fell swoop.

The pressure gauge I got has a solenoid, so I was planning to run on a
timer with the light hood, so the CO2 unit will ultimately be on for
about 9 - 10 hours per day. Mostly, I just don't want to come down
after the first day to discover 15 dead rainbow fish.

Currently, the tank contains several java ferns, two sword plants, a
micro sword, and an anubias.

Any tips from you pros would be appreciated,
Andy


In addition to Nikki's good advice, try an initial setting of 5-10 PSI
on the pressure regulator. The method of using the pressure setting to
adjust flow rate will not provide a stable flow. The needle valve
adjustment is sensitive but usually you can get it to stabilize at a
suitable flow rate.

You can tweak the pressure setting and needle valve many times a day,
to get a specific bubble rate. But give pH most of day before you
readjust. For example: set in morning, recheck in evening.

It is a good practice to use a check valve in the CO2 line between the
bubble counter or needle valve, and the diffuser. I have used the
little black Tetra ones successfully, probably most of them will be
fine. No need to buy expensive CO2 tubing or check valves. It would be
much cheaper to replace with standard air hose and components every 6
months. The soft and flexible silicone tubing is a little easier to
work with than the clear PVC tubing.

--

I have one 110 watt compact fluorescent and a 40 watt regular
fluorescent.

I know that isn't great for a 75 gallon, but it's a step up from just
having two 40 watt tube fixtures on there. If it looks like the
plants are languishing, I can try to add more light, but it "seems"
pretty bright with the current set-up. Don't want to have people
getting blinded just from sitting in my living room. ; )



On Thu, 16 Feb 2006 15:11:10 +0000, Nikki Casali
wrote:

ah wrote:

I have a 75 gallon tank with about fifteen rainbow fish. I've ordered
CO2 equipment which should arrive this week.

What's the best way to start this up? Do I just run it for brief
periods of time at first, like an hour a day, and gradually build it
up? I don't want to make any massive changes in the tank chemistry at
one fell swoop.

The best way to build up is to start with a low constant bubble rate.
Start with one bubble per second. Wait a couple of days, then check the
pH to see how much CO2 is being dissolved. Gradually increase the bubble
rate over the course of a week until your preferred pH has been
achieved. Check that once you've set a bubble rate it stays put and
doesn't wander. I have a cheap regulator that changes CO2 flow depending
on ambient temperature (not good). I use a pH controller to overcome that.

The pressure gauge I got has a solenoid, so I was planning to run on a
timer with the light hood, so the CO2 unit will ultimately be on for
about 9 - 10 hours per day.

I use a solenoid linked into the lighting timer on my 16 gallon tank. I
have it on 12 hours per day. When the lights go off, the CO2 flow is
stopped. I don't find that the pH changes much over the course of the
night as the plants start expiring CO2 anyway. I have the bubble rate on
this tank set to 1 every 3 seconds. It's only 16 gallons so it doesn't
require much CO2. My 75 gallon requires at least 2 bubbles per second.

Mostly, I just don't want to come down
after the first day to discover 15 dead rainbow fish.

Start with a constant, low bubble rate and don't let anything or anyone
modify the setting accidentally.

Currently, the tank contains several java ferns, two sword plants, a
micro sword, and an anubias.

My java ferns are always covered in small bubbles of oxygen. How many
watts of lighting do you have there?

Nikki