Amongst other things I joined this forum to try and find more info on using Mazzei venturis so as this appears to be the only specific mazzei/co2 thread forgive me for resurrecting it - my experiences might be of some use to someone. Apologies for the length
I have tried various methods of diffusing CO2 into my (180l) tank and following some success with diy venturis (basically stepped hose connectors cut in half, reversed and re joined with rigid tubing) I bought one off ebay - it has 1/2 inch threads, an internal diameter of approx 4mm and looks just like a mazzei (384?); definitely not a Kent !
To test it I just connected it to the output of my canister (rated 1000l/h but giving approx 500 l/h) and observed. Firstly with no co2 line the performance was pathetic - my diy venturis produced a torrent but this hardly pulled any air through at all! However, when I connected co2 it came out as a very fine dust - better than the diy versions which still gave tiny
(limewood airstone size) bubbles. Flow had reduced to about 300 l/h which wasn't a problem as I use a Koralia for circulation. My setup obviously doesn't generate enough pressure and/or differential to initiate significant air suction but still manages to crush the co2 as, presumably, it is forced in under pressure.
Whilst waiting for some connectors to arrive I just pushed hose over the threads and connected it straight to a spray bar in the tank. Results were excellent - even with the koralia off micro bubbles gently spread everywhere and the plants pearled better than any other method I've tried. Since then, without spending much and with a spare 800 l/h external pump I've tried to improve pressure/differential as per suggestions on the mazzei site but none worked given the low
source flow/pressure. I did manage to get a finer mist by connecting the external in series between the canister and the venturi which increases pressure (add the pump heads) but in my opinion the improvement wasn't worth sacrificing simplicity for extra compexity and power consumption.
So bottom line - the venturi does an excellent job of misting my tank at an economical bubble rate (2-3 b/s) and without extra equipment. It's outside the tank, has no moving parts and should be relatively maintenance free but it does reduce flow significantly. All in all I'll stick with it but will probably try and get a bigger pump or filter when I can afford it.
I have tried various methods of diffusing CO2 into my (180l) tank and following some success with diy venturis (basically stepped hose connectors cut in half, reversed and re joined with rigid tubing) I bought one off ebay - it has 1/2 inch threads, an internal diameter of approx 4mm and looks just like a mazzei (384?); definitely not a Kent !
To test it I just connected it to the output of my canister (rated 1000l/h but giving approx 500 l/h) and observed. Firstly with no co2 line the performance was pathetic - my diy venturis produced a torrent but this hardly pulled any air through at all! However, when I connected co2 it came out as a very fine dust - better than the diy versions which still gave tiny
(limewood airstone size) bubbles. Flow had reduced to about 300 l/h which wasn't a problem as I use a Koralia for circulation. My setup obviously doesn't generate enough pressure and/or differential to initiate significant air suction but still manages to crush the co2 as, presumably, it is forced in under pressure.
Whilst waiting for some connectors to arrive I just pushed hose over the threads and connected it straight to a spray bar in the tank. Results were excellent - even with the koralia off micro bubbles gently spread everywhere and the plants pearled better than any other method I've tried. Since then, without spending much and with a spare 800 l/h external pump I've tried to improve pressure/differential as per suggestions on the mazzei site but none worked given the low
source flow/pressure. I did manage to get a finer mist by connecting the external in series between the canister and the venturi which increases pressure (add the pump heads) but in my opinion the improvement wasn't worth sacrificing simplicity for extra compexity and power consumption.
So bottom line - the venturi does an excellent job of misting my tank at an economical bubble rate (2-3 b/s) and without extra equipment. It's outside the tank, has no moving parts and should be relatively maintenance free but it does reduce flow significantly. All in all I'll stick with it but will probably try and get a bigger pump or filter when I can afford it.