Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations fish recovery system

For those interested, I picked up an oxygen flow meter at a local medical supply company for 10 bucks. It is in great condition. Just one of their rental's that are now the older style they no longer rent out. So, if and when you guys decide to put together a fish recovery system like George or Al or a fish transport system check with your local medical supply companies.

Great idea !! In all the years on the Forum I have not heard anyone suggest that a medical supply company might have helpful pond items !! Well done Tracy !!!

How does this help? How would you source cylinders of oxygen or refill them? Does the usual source for oxygen cylinders not come with a way to regulate them?

Either buy a used medical oxygen generator or contact a saltwater bait camp. They use them to keep croakers lively for bait for specks and redfish .... also any welding supply has the small oxy bottles and regulators

I think the small oxy bottles are about 8$ each to refill

Thanks Eric. The system I put together came from a photo here from Fireishot (Al). I looked for the thread but was not able to locate the Picture of his system and I no longer carry a phone to the pond after loosing two of them in the pond. So no pic right now. And Canyoncreek, yes you can purchase a regulator and O2 tank from your local welding supply company and that is what I did. Cost was less than a hundred and fifty bucks including the air stone from Pintair. But with the regulator they sell, you will go through the O2 two fast. Al told me that, but I had to try out the system and he was right on. O2 was gone after using it on just two fish. The flow meter will give you more control of oxygen amount being used. Just contact your local medical supply company and ask if they have any flow meters they no longer rent out and would they like to sell one.

I am in the process of putting together a system like this and just ordered the Point 4 diffuser and was planning to pick up the regulator and bottle today. However, I wasn't aware of the regulator issue you are referring to. What psi were you running? They recommend about 35 psi, I think, and I have noticed that some welding regulators only go down to 50 psi. If it was running at 50, I can see why it would go faster so I sure don't want to get one of those. I believe the George said in another thread that he gets about 10-12 hours use out of his 20cf bottle.

I notice that all of the O2 flow meters are calibrated in liters per minute (flow) and not psi, per se. How does that translate? What do you have your flow meter set to?
Thanks

following

The regulator on the O2 tank sets the PSI for the Pentair diffusers. 30-35 psi is what I set mine on. If you go higher than that, you can ruin the diffusers. The flow meter is for lpm, and the settings can change a little each time the rig is used. As a rule, 1-2 lpm is what I set my flowmeter at. That's based on the look of the O2 surface bloom, but not the actual number I'm seeing. The amount of O2 used needs to be enough to break the surface tension, but not look like a rolling boil. More of a surface simmer, not a surface boil.

If rainman or esshup see this thread, maybe they can throw some better info out. The above info is just what I've gone by here.

I appreciate the info! I was only planning on getting a regulator but I see now that I need both a regulator AND a flow meter. I guess if you just let her rip at 25 psi and let the diffuser be the only restriction then your tank would be gone pretty fast.

Depends on the airstone. The micro bubble diffusers found in this link flow very little at 23-25 psi but do a tremendous job of oxygenating the water. It takes around 23-25 PSI to actually see bubbles with them. In fact, I have often set the PSI at around 20-22 PSI and the 02 in tanks would climb to above saturation (with light load) without any bubbles reaching the surface. Smaller the bubble and slower the flow=best (oxygenation). Larger the bubble and more flow=bad (aeration). I could get around 24-36 hours of hauling time with a 300 gallon tank and two airstones running with a single O2 cylinder (300 cu ft).

https://pentairaes.com/point-four-micro-bubble-diffusers-mbd.html

i use the Point Four diffusers. I set the regulator at 40psi (diffuser range is 30-50psi) Normally, I can haul 200 pounds of fish in 135 gallons with a 4lpm. The ceramic diffuser makes bubbles so small that many dissolve into the water before surfacing. I generally set my flow rate similar to how Fireishot described. A lot of times, I have to see the water surface at a sharp angle to see bubbles breaking surface tension....much more oxygen flow, and the O2 is just wasted....Watch your pressure because as tank pressure drops, output pressure increases. Pressures over 50psi can blow the diffuser apart and cause a leak....if a leak happens, you could empty a tank in as little as a few minutes.

If using the smallest Point Four made, max flow is 4.5lpm. A "K" size O2 tank has 80 cubic feet (~2300 liters) at 2000psi when full without a flow meter, that small tank (largest size sold to general public) would be empty in about 8.5 hours.

I run 8 large diffusers, and like acoursey, use the "T" size O2 tank. The T is said to hold 300 cu ft, but I'd say it is more volume due to the pressure being 2500psi whn full...I can go a week on 3 tanks of O2 hauling 1500 pounds of fish. O2 is actually less of a worry hauling fish than water quality is...fish that have eaten recently can create a LOT of ammonia in very little time! Try getting fish that have not been fed in about 3 days and be prepared to change water immediately if the fish do not go to the bottom when the haul tank lid is opened, or if fish looked stressed, or swim erratically (sign of ammonia poisoning).

Great information guys, I really appreciate y'all taking the time to educate myself, and others, on this subject. Nothing beats real world "been there, done that" advice!! My plan is to use a 48 qt ice chest on wheels and a 20cf oxygen tank. I already purchased a Point Four, PMBD 75, which I believe is the smallest model they make, so now I just need advice on the regulator/flow meter. Is a regular Victor brand welding O2 regulator ok? And, is there anything in particular to look for in a flow meter? Thanks again for all of your advice and help!

JKS, Rex(rainman) and I may disagree about the regulator because his O2 requirements are much more critical than mine, but I didn't spend a lot of money on the one I have. I got mine from my welding shop, and asked for the cheapest generic regulator they sold that nobody came back in complaining about. It's held up fine.

I keep 3 of Harbor Freight's finest single stage $40 O2 regulators for each trip. I keep extras in case road debris trashes a gauge or regulator T screw falls out somewhere...Regular welding is just fine, cheap is better!

https://www.ebay.com/p/Allied-15009-03-T...id=263869327675 Male threaded portion is usually 1/2" acme thread...often a 1/4" hose barb X 5/16" female inverted flare thread adapter fitting works and seals

Got it, cheaper works for me! Thanks again guys!!!!!

JKS3613's O2 recovery system

Good job Al, posting the linked photo and thread.