Well I have a horror story for all those who inject co2. Sometime in the middle of last night my co2 diffuser popped off the co2 tubing. Which then let the full pressure of the co2 pump unhindered into my tank. Well the ph dropped from 6.8 to somewhere under 5.0 and all my fish were dead! 2 discus, some 20ish tetras, twig cat, 3 blue rams and 1 bamboo shrimp. DEAD!!!!!
I know it takes a long time to saturate the water with co2 but its not worth the risk to let it run 24/7.
Well I guess you live and you learn.

Oh man that sux, sorry to hear that. what kind of diffuser did you have? I would think that the bubbles would have rose to the top and degassed.. Man i'm sorry for your loss

...sorry for your loss, but that's why I recommend people to run their CO2 on a solenoid and have it turn off 5-10 minutes prior to lights-out.

Also, it doesn't make sense why your CO2 diffuser popping off will lead to MORE CO2 into your tank since the bubbles are much larger than with a diffuser. If you set the needle valve at 3bps, for example, it should stay at 3bps whether a diffuser is attached or not.

I bet you what happened was an end-of-tank dump with caused a huge release of CO2. In turn, this made your diffuser pop off, and despite the larger bubbles w/o the diffuser, the tank dump put enough CO2 into the water to kill your fish. Get a low pressure regulator with release valve to prevent this in the future.

What's the reading of the tank pressure on your regulator? Less than maybe 700 psi?

First off, I'm sorry for your loss. I would be heartbroken to lose those fish! But something doesn't quite make sense to me either. If the tubing popped off the diffuser, the CO2 bubbles would have been quite large, and most would have floated to the surface and escaped into the room. Also, the diffuser doesn't really restrict the flow of CO2. Well it does add a bit of back-pressure, but certainly not enough that the loss of it inline would allow for an unhindered dump of your CO2 tank. Was your tank empty in the morning? What do you have inline after your primary regulator? Sounds like an end of tank dump to me as well.

I'm wondering about the reference to a CO2 pump. That's something I've never seen nor heard of.

On a correctly setup CO2 system your problem could not happen. First off there would have been no large increase in the amount of CO2 going into the system. Second as stated the larger CO2 bubbles would have just risen to the surface quickly and very little of the CO2 would have dissolved into the water due to the short amount of contact time vs the size of the bubble.


And about 35-40% of people run CO2 24/7. And almost everyone with DIY runs it 24/7. Running CO2 24/7 is actually quite safe on a stable system.

hear is what happened. The diffuser was a glass one that came with the regulator but I see it sold for 15$. It was clogged, I guess. So once the presure built up I wasn't getting more than 1 bubble per minute, so I turned up the pressure so I was getting about 1bubble every 3 seconds. Not knowing that the diffuser was clogged so when it blew there was co2 pouring into the tank at probably 100bps. This is how so much ended up in the water.
As far as the reading on the gauge goes I don't seem to understand it. When the valve is opened the gauges go up and regardless of what I do with the adjustments they seem to stay the same. so I use the bubble counter to judge the pressure.
I just got a new one for this tank today. An ADA one.
The death was caused by the rapid ph drop. My kh was only about 30ppm.

when you open the big knob on your co2 tank sufficiently, the upside and downside pressure should be constant. it will only decrease as you use the co2 up

Death was not due to pH drop. Death was due to high concentrations of CO2.

High side gauge shows cylinder pressure. This will remain constant (at a constant temperature as it is affected by temperature) until all liquid CO2 is gone from the cylinder.

So my question is did you change the low side pressure or open up the needle valve?

Low side gauge shows the set working pressure of the regulator. This will remain the same till all liquid CO2 is gone from the cylinder and then will normally increase. The other thing that will change this reading is the user.

Bubble counters don't judge pressure. They show a basic approximation of flow rate.

Today I got the ADA diffusers in the mail. The difference is unbelievable. With the needle valve just barely open co2 is being diffused. What I did was turned up the pressure until co2 was coming out of the diffuser. Which ended up being about 1 bubble every 3sec.

This will not happen again.

The correct way to do it is to use the needle valve to control the flow rate and not the regulator adjustment.

You're saying the cheap diffuser was "clogged", so that's why when it popped off, you were getting this huge influx of CO2.

If, for example, at your needle valve you were letting 100 bubbles of CO2 through per second and the diffuser only let 3 bubbles out per second...where did the extra 97 bubbles go? The regulator-to-tubing or tubing-to-diffuser interfaces aren't "strong" enough to account for the difference you saw. I'm just using approximate numbers. Even if the needle valve is cranked to 5bps, there's no way that your diffuser is letting only 2bps through for an extended amount of time. Where does the extra CO2 go?

You have a bigger underlying problem...

I really don't know. all I know is thats what happened but that won't happen again I got good products.