Mazzei build thread

[krap101]

I guess this is a good a time as any to start my first build thread. I will be using a Mazzei injector for co2 injection into my 29 gallon (possibly my 40b once I get it running). The concept behind the Mazzei, is the volume of water running through is compressed into a smaller space, and when it reexpands, it also creates a sort of vacuum (venturi effect). This is where we insert co2. Because of the expansion process, it creates turbulence, and this is how the co2 is diffused. As found out by many people on some other forums (namely plantedtank and Tom Barr come to mind) that having co2 microbubbles dispersed throughout the tank is more effective than diffusing the co2 directly into the water. More co2 gets to the plants, and their tests have shown that plant growth is as good if not better than normal reactors. This kind of injector is especially helpful if you have some sort of sump with a return pump with a reasonable head height (read psi). So, the injector is put inline with a bypass to control how much the co2 is diffused or broken up (by controlling the amount of water going around the injector and therefore the amount of water going through the injector as shown here:

Mazzei's have been done before, and have been around for awhile, but I've only found one build thread that has successfully integrated it into the return of a canister filter.

So here is my canister filter

Sunsun HW-302B

Here is someone else's review

SUNSUN HW-302 Outside Filter setup & test - Aquaria Central

I did my own head height test, and I got a little over 7 ft. That means I have between 2-3 psi (their lowest rating is at 5, so this is why these thing need to be tweaked)

The biggest thing I've read about is the pressure differential across the injector. This concept confused me a little, but a few emails straightened it out (I hope). The pressure differential would be the amount of water pressure downwards exerted by the tank (so if I have 18" of water above my canister, and I have a head height of 78", that means the inlet head height will be like 60" and the outlet head height will be around 57" or so. If I end up putting the injector above the tank, that means I will have a positive value, so the inlet head heighth will be 78-18+2" (lets say the injector is 2" above the tank) or 52" and an outlet pressure of around 0 psi.

Sorry if that was confusing, but I didn't want to have to convert everything. But the formula is .433*head height (in ft). So, my pressure differential will be around 1.9ish psi

Please correct me if I'm wrong, this just got confusing again when I did it.

I tried a smaller model, before talking to the mazzei engineer, and my canister could not push enough water through, (even without the bypass). Flow came to a trickle, and that is why it is on ebay/classifieds waiting for someone with a stronger sump to buy it

Anyways, sent an email out recently, deciding on which model I will be buying next. I know I'm getting a 584, but whether is is the regular (584) or 1/2" model (584C), I don't know yet.

So, until I get my new injector, please feel free to offer any suggestions or ask any questions

 

[krap101]

My injector came today, but I screwed up my bypass, so I'll buy some more parts, glue it, and come back with pics later.

I just tested it without the bypass. 100% diffusion. With the bypass, it should make the bubbles really tiny and this project will hopefully turn out to be a success!

 

[taylorodw]

That is super cool

Thank you for teaching me something new! Have you calculated your CO2 level?

 

[krap101]

Lol finally thanks taylor..

Anyways.. I'm kind of scared to run it. With my glass ceramic, I'd guess I got maybe 50-70% diffusion, not including outgassing after dissolution. This setup with give me beyond 100% (there will be more co2 in the water than would normally be possible)) because the bubbles will float around in the water, and stay there for awhile. I've had several accidents with co2, and this will just make it more dangerous ><

Anyways, so I bought all the parts for my bypass, I'll set it up tomorrow morning/afternoon, and try to record the size of the bubbles that come out. If you're going to try this, be very careful, because your pH can crash in a very very short amount of time.

 

[taylorodw]

I would get tank water during a PWC, stick it in an empty aquarium (if you have one) and test.

 

[krap101]

I'll build my bypass today, and if I don't screw up, it will have cured by tomorrow. I'll start at 1bps and go from there.

I also changed my design a little to allow me to to remove the mazzei more easily without having to destroy the bypass to get to it injector using unions. I've also increase the diameter of the pipe to 3/4, since my hose is 5/8, it seemed like a better fit.

If something comes out and cloggs the mazzei, (that would mean something has to get through my canister, but it's possible, since mts end up everywhere... ) I would need a way to remove it. I'll start testing tomorrow, and I'll add pics tonight

 

[HN1]

Definitely tagging along on this.

 

[krap101]

Uugh, I ended up working on my pond today, and didn't around to glueing my bypass. It's wet outside, which was another deterrent.

Here's a pic of my first unglued bypass for reference. It was made for the smaller injector which didn't work, so I had to make a new one.

This is a picture of the injector itself (584C)

 

[krap101]

Anyways, I finally finished the bypass. I'll let it cure tomorrow, and I'll have my first tests and a video for tomorrow. I did take a lungful of what I assume to be acetone.. Not fun...

Here's the picture of the finished one. I decided to make it upside down to reduce output pressure (very little water to cause downward pressure for the output) so it's alot higher than many you see. I can do this and make it not be ugly, since I will stand it up behind my tank and I have painted the back black. Excuse my crappy priming job. I don't work with these solvents very often, and they sometimes.. drip and stain everything.. Luckily none got on my white shirt

I'm also assuming that the extra distance for the bypass won't cause any major ill effects besides a little extra friction from the increased distance.

 

[krap101]

I'm currently playing around with the "settings" and seeing what effect the flow has with the size of bubbles. I'll post a video in the next few hours, after I make sure my fish don't die this time.. (bad experiences with co2 and SAE's), and I'll be sure to closely monitor it this time.

Btw, hn, the chain swords are putting off runners, and the ocelot sword is turning reddish brown. (I think the chain sword is my new second favorite plant, after dwarf hairgrass). The micrograss is doing well, and as you gave me so much, I'm starting to grow some outside . I floated it in some peat/water with some garden mix, and when the water evaporated, it buried the plants 1-2", and now the first runners are starting to pop out.

Here ya go.

 

[krap101]

I've hit a little burp, something I hadn't expected earlier. One side effect of the "misting" method is that there is a delay between the time where the co2 is injected and there the bubbles actually dissolve. I have my solenoid in sync with my lights, so when my lights went off, and I went to bed, I started hearing some splashing noises (when cories dart to the surface) and didn't think anything of it. I remembered my bypass was leaking a little, so I went to check on it, and saw my fish at the surface, once again, gasping for air. Luckily I caught this one before I went to bed, and have the spray bar pretty high, but it looks like I'll need to put the co2 on a different timer that ends a little before the lights. This all happened in like a 15-20 minute period, even with the co2 being off..

I checked today, and no deaths, thanks god. I'm between 2-3 bps right now, and I didn't know that the plants made that much of a difference in co2 levels..

 

[taylorodw]

Be careful!

Wow it sounds like a powerful setup. That video was just an error when I tried to view it, though.

 

[krap101]

?

YouTube - Mazzei Mist

 

[krap101]

After another minor incident yesterday, I realized that surface agitation won't affect this build since it's not using the normal modes of diffusion. I can have optimal gas exchange at the surface, while the micro bubbles drop into the water. I just need one of those koralias to create some circulation below, so the bubbles want to drop. This is turning out better than I thought.

 

[taylorodw]

How much was the injector again?

Theoretically this would affect flow less than a Griggs style reactor, right?

 

[krap101]

I got it for like $45 shipped or something like that. I'd imagine that this would restrict flow more because of the constriction at the center of the mazzei. My spray bar is starting to slow down, and I'm guessing it's because I need to clean out my canister or finally cut the tubing to its final size or something. It might also be because my bypass is huge, and it might restrict flow less if it were less deep.

I won't know until I get my wavemaker on maybe thursday, because I had another mini-incident yesterday... I had the spray bar above the water with agitation, but there was still a mini co2 overdose after lights out. I was running maybe 1-2 bps during the day, and the co2 turned off with the lights.