[APD] Re: Lights and CO2, Amano

[Thomas Barr <tcbiii at earthlink_net>]

>I ask about this every 5 years on the net. So now it's
>a good idea? For 20 years it's been "uh...".

>Is there consensus on photoperiod these days? 12? 16? does
>it matter?


This notion of a 3-5 hour blast, or mega dose is similar to the nutrient pulse right before a water change.
Add lots of CO2, nutrients and light and then back off.

CO2, lights we can do this easily.

I do this also.

I never add CO2 24/7.
Neither does Amano.
While many like to do this and have few problems, the end result is that you simply do NOT need CO2 at 20-30ppm at night.

The whole issue of whether pH variation when you stop adding CO2 is bad at night is unsubstaniated based off my own and many others, Amano among them on fish health.
pH change due to the addition of baking soda is quite another matter.
But pH variations due to CO2?
I've never seen anything that suggest this is negative.

Chronic residual levels of CO2 are also more difficult to maintain than a simple "blast" for 8-10 hours.
I can add more CO2 during this time than anyone can using a pH controller and not harm the fish.
40ppm during peak photosynthesis under very high O2 production works very well.

Think about that for a moment.
Then think some more about it.

This gives the aquarist a down time peroid where any excess CO2 can out gas.
O2 levels drop off as the CO2 levels decline.

This produces less stress on the fish.
This also gives you a great deal more wiggle room with dosing CO2.
Dosing CO2 is the biggest issue for aquarist in general.

We add CO2 for the plants, not to maintain a stable pH for fish. 
pH and Kh can be used to measure CO2, but that is all it is in practical terms.
People have been saying that pH swings are bad due to plant uptake of CO2.
Well what the heck happens everyday in natural systems?

We add CO2 when? During the day for the plants. When the plants will use it and influence the pH.
Plants do not use CO2 at night, so don't add it, it's not needed.
If you use a solenoid, this will double or triple your use.

You also do NOT need 5 w/gal of light for 12 hours.
If you like techy stuff, a pH moniter works great.
If you like nuke powered lights, adding an HQI for 4 hours to a PC set works well
But George, myself, Amano, Claus, Karen, most folks have said, you do not need all this light.

It means the tank will use more CO2, more nutrients and more pruning.
If you want that, cool, but I hear a large group of folks that want less pruning, and more stable tanks, add less light.

It does not have to involve a HQI light for 3-5 hours either.
Large tanks take some time, so called "LAG" time for the CO2 reactor and the water to achieve good CO2 levels.
After 4 hours or so of vigorous plant CO2 uptake, often these CO2 reactor set ups cannot respond and mix the CO2 effectively into a tank.

I see this often.

Then they get algae and blame the nutrients...........

But it's the CO2, then they say well my CO2 is 30ppm. I ask "when?"
How effective of a response time does the reactor need to get the CO2 up to 30ppm?

Many CO2 systems have issues with this. Poor mixing, offgassing, controllers that are not set high enough to keep the pH stable during the midday peaks, poor flow through the CO2 reactors etc

I'll discuss this more in depth in the BarrReport.
It's a topic that needs addressed as many folks that appear to be doing things correctly still need to tweak their CO2 systems and have them do the job they were designed to do.

Regards, 
Tom Barr






  

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