Happy spring, all!

The system that I inquired for guidance on last year is back up and running this season! Thanks again for everyone who helped me think through that.

[img]https://photos.app.goo.gl/WBURwXt38Jbf9zpT9[/img]

As I mentioned at the end of that thread (but never got around to trying late last summer), I'd like to try expanding the setup a bit to two diffusers.

To recap:

I started pretty small & simple - a single 9" diffuser on 50 feet of 3/8" airline, powered by the HIBLOW HP-60. HIBLOW specs say this puts out 60lpm and 2.13 PSI.

The Matala diffuser lists air inflow range as 0.88 to 3.53 CFM, which converts to 24-98lpm.

I'd like to add a 2nd diffuser, towards the other side of the pond.

Ideally I'd like to go ~75-100 feet with the 2nd line. Is 3/8" still Ok for this?

And, more generally - will I be bumping up against the lower end of the diffusers' inflow range?


Any other concerns / issues with this plan?

I would go with 1/2" ID line. You can thank me later. LOL Swap out all the line for 1/2"-0.6" ID and your compressor will thank you.

Ok, understood - thank you!

Any other thoughts - for example, about the diffuser's inflow range?

Well, I think you mis understood how the disk type diffusers work. By reading the other thread, I assume you think that medium to coarse bubbles will move more water than fine bubbles. The opposite is true, fine bubbles move more water to the surface, which exposes more of it to O2, therefore more O2 is added to the water.

Since it's a DIY system, you have to do the homework. Talk to the diffuser mfg and see if you can get any specs as to how many GPM the diffuser will bring to the surface at "X" depth and with "X" CFM of air. That way it will allow you to properly size the compressor by looking at the pressure/volume curve.

"HIBLOW specs say this puts out 60lpm and 2.13 PSI." What water depth will the diffuser be placed at? Do you have a pressure gauge on the air line near the compressor? If so, what is the running PSI? If you don't, you really need one because without it you are just guessing.

Going with 2 diffusers, you will have to run 2 individual air lines, each with a ball valve to control flow rate. That ball valve will be used to balance air flow rate to each diffuser.

Thanks again, esshup.

Although I'm pretty sure your questions were intended for my own processing, I'll post responses here as well:

- What water depth will the diffuser be placed at: 6-8 ft

- Do you have a pressure gauge on the air line near the compressor: I don't - so I'll need to look into this..

Buy a low pressure air gauge 15-30psi. 2.13 psi puts air out down to about 5 ft deep and then air flow as cfm starts to be restricted as depth increases and diaphragm wears prematurely.