Jason,

DC green is shorthand for stating that my drop checker (DC) filled with a 4kh solution shows a nice green color.

I have several of them and move them around the tank to ensure adequate c02 (I hope) all over the tank.

Per our measurements, this is between 30-40 ppm of c02.

This is not exact science, but what we hope to get.

This is an indication that c02 levels are adequate, but not confirmation.

It usually takes between 2-4 hours for the color to reflect your tank. That is why they are an indicator only...........

Other important factors with CO2:

Good current, some surface movement(you still need O2 from the air above), simply watching the plants and the fish.
Slowly adjust things up from a low set point.
Keep a good eye on fish, do not base it on one day's behavior, give it time before as well as the plants. Plants will do very well if there is plenty of CO2.

Regards,
Tom Barr

Got it, just didn't know what you meant by "DC" ... it helps to spell it out the first instance you use it and put the acronym in parentheses behind it: drop checker (DC). Then you can use the acronym from then on and any reader will know what you are talking about.

We're getting waaaay off topic here. All I wanted to know is what the practical differences, ignoring the connector size (ie. 1/2" vs 3/4"), are between the 384 and 484 Mazzei...

What's the practical difference, if any, between the "PVDF NAT" and "PVDF BLK" other than $22 more for the former?

Is it just color?

Take a look at the picture below under the AIR SUCTION heading. Look at the Motive Flow GPM of each model and it's corresponding Air Suction SCFH . As shown, the smaller Mazzei generates more suction at the same GPM as the bigger model as the outlet pressure increases. While the 484 might have a tad more suction at 0psi outlet, this cannot be used to accurately gauge the size needed therefore it's best to start looking at the numbers higher than 0psi. Why? Realistically once the Mazzei is installed on a typical plumbing setup the outlet will have some resistance, hence the need to look above 0psi.

This is the reason why it's suggested to use a high head pump so that high inlet pressures can be applied, the higher you can provide the better the mist/co2 dissolving will be. In the Mazzei world bigger injector does not mean better and this is where most fail.





Better Chemical resistance I believe.

Ah! Thank you!!!! While I sort of understood the number charts to a limited extent, deciphering it was the problem! Okay, so say for a ~350 gph pump with 1/2" input and output on a 20-long tank{1}, I would probably be better off with the smaller of the Mazzei's as this would theoretically provide the best suction and dissolution of the CO2 with the water. Am I getting this? An injector such as the 284 would be the more useful choice most likely, no?

-Jason

{1} Just as an example, it's currently my test tank. I'm getting quite good lately at growing BBA, actually.