How can I prevent this from happening again?

[A. Nonymous]

As I mentioned in another thread, my CO2 went wild in my 75g tank and wiped out my entire fish population. This isn't a thread to cry about my loss or plan a restock, I'm wondering what I can do to prevent this in the future. I've got a 10g tank and a Milwaukee regulator. What's the best way to keep an even flow of 2-3 bps without it going nuts again or stopping altogether?

[WinnipegDragon]

A pH monitor connected to the solenoid on the regulator is probably the safest bet...

[jmhart]

Without knowing the reason your co2 went out of control, I can't really give you a good answer. Here are a couple ideas.

Chances are your needle valve was opened up accidentally, either this or it was set too high to begin with and the regulator was opened up further. Preventing either of these is difficult using the Milwaukee setup. Once the needle valve and regulator positions are set, there is no way to remove the turn knob of these devices. There are regulators and needle valves on the market that either A)require a screw driver to adjust the setpoint or B)have removeable knobs. If this is a very strong concern of yours, you can sell your regulator on ebay and buy one of these. Pacific Coast regulators are like this, at least for the regulator pressure(not the needle valve).

My other guess is that you had the co2 set too high to begin with, but it wasn't high enough to kill the fish before lights out and when you woke up in the morning they were dead. The way to prevent this is to have your co2 on a timer, shutting off at lights out and coming on an hour before lights on...this way when the co2 is on, you can see what's happening. This isn't perfect, but it helps.

And finally, you can also use a pH controller, that will open and close your solenoid valve depending on a preset condition of your tank. This way, even if the needle valve is open too far, once your co2 hits a certain setpoint, the solenoid will close and not release any more co2.

[A. Nonymous]

This was a situation where the tank ran fine for about 6 mos. Then one day I woke up to see the filter spewing out huge bubbles of CO2, the bubble counter going nuts and the fish all dead. I hadn't touched any of the settings before this happened.

[tanker]

Get a good regulator, this should help. But a PH monitor is the best idea.

I have a PH monitor but it is not connected to my regulator. My system has been running for years.

[A. Nonymous]

I see several on ebay. Is there any one that's better than the rest?

[jmhart]

I don't use a monitor, so I can't really answer which one is best.

However, what you are talking about sounds like "end of cylinder dump". Regulators typically used in aquariums aren't capable of maintaining low downstream pressures at low upstream pressures, so when the cylinder drops below 75-100psi, it starts to dump, flooding your tank. A good needle valve or more expensive regulator can help this, as well as a pH monitor.

[Ajordan]

empty cylinder dump would be my guess as well...

[A. Nonymous]

Wow. It's almost like you've done this before. :) This happened last Saturday. I've had the cylinder running with just the plants since then. The pressure is reading at just a shade below 100. It's at about 90-95 psi.

I've got a needle valve on the tank, but I had it all the way open as that's how the instructions recommended.

[Fordtrannyman]

High Side 90psi?
The tank is done. Try not to let it run all the way out. There's trash and micro-particals that will lead to restrictions eventually.

[Fordtrannyman]

Milwaukee regs. are kind of finicky.
The best way to run this reg. IME is to set the low side to 20 psi and adjust the bubble rate with the needle valve. (That's why we have a needle valve!) The directions are wrong, plain and simple.
Furthermore the low side gauge will fail if you do not close the regulator completely (by turning it counter clockwise), before opening or closing the tank valve.

I hope this helps.

[A. Nonymous]

High Side 90psi?
The tank is done. Try not to let it run all the way out. There's trash and micro-particals that will lead to restrictions eventually.

It's on the low side. I assumed I could just run the tank until it was completely empty. Clearly I didn't do as much research as I thought I did. I'll close the tank for now and put filling it on my budget when I get the money.

[A. Nonymous]

Milwaukee regs. are kind of finicky.
The best way to run this reg. IME is to set the low side to 20 psi and adjust the bubble rate with the needle valve. (That's why we have a needle valve!) The directions are wrong, plain and simple.
Furthermore the low side gauge will fail if you do not close the regulator completely (by turning it counter clockwise), before opening or closing the tank valve.

I hope this helps.

I just re-read this and realized I don't entirely understand it. There are two guages on the regulator. One on the right and one on the left. Which one are you referring to as the "low side"? Also, when you say I need to close the regulator completely, what exactly are you referring to? The black knob on the front needs to be turned all the way to the left before opening the tank? I'm a little unclear as to what you're saying.

[jmhart]

When dealing with any fluid system, people refer to things as "upstream" and "downstream". These temrs are in reference to a single point of control. In our case, following the path of the gas, "downstream" is anything after the gas pases through the regulator, and "upstream" is anything before the gas hits the regulator. By regulator, in this case, I mean the infintesimal point where the gas drops in pressure. So, when he says "low side" he's talking about the downstream pressure gauge. This would be the one that reads the lower pressure, look at the gauges, one reads high pressures, one reads low pressures. On the Milwaukee(as well as most other regulators unless they are specially made) the "downstream" or "low" pressure gauge is the gauge on the left(if you are facing the regulator). Conversely, "upstream" or "high" pressure is the one on the right.


And yes, you need to keep positive pressure inside the cylinder or else it can get blow back, which is dust and any other particle that could cause contamination or regulator malufunction later. Anything under 100psig makes it hard for the Milwaukee Reg to maintain good downstream pressure so I like to exchange my cylinders at 100 psig, but the lowest you should ever go is 50 psig.


And finally, regarding "closing" the regulator. What he means is that you need to turn the regulator knob(not the one on the cylinder, the one on the regulator) so that it is all the way counter-clockwise. This drops the downstream, or low side, pressure all the way to 0 psig. You do this as a safeguard to protect your gauges. If you have the knob turned too far in the clockwise direction you can blow out your downstream, or low side, pressure gauge. They don't actually explode or anything, it's just the pressure can be so high that it bends the pressure sensitve spring so that it either A)no longer works at all or B)no longer works accurately.

The gauge is replaceable, for a price.

[Fordtrannyman]

On the Milwaukee(as well as most other regulators unless they are specially made) the "downstream" or "low" pressure gauge is the gauge on the left(if you are facing the regulator). Conversely, "upstream" or "high" pressure is the one on the right.

This backwards jmhart!
While reading the gauges...
High side is closest to tank-on the left
Low side is output-on the right.

[Fordtrannyman]

It's on the low side. I assumed I could just run the tank until it was completely empty. Clearly I didn't do as much research as I thought I did. I'll close the tank for now and put filling it on my budget when I get the money.

Be sure to cut the lights way down to avoid algae outbreak.

[Fordtrannyman]

There are two guages on the regulator. One on the right and one on the left.
Normally. What model is it? Did you get it new?

Which one are you referring to as the "low side"?
On the Right, nearest the output. The solenoid usually attaches to it.

Also, when you say I need to close the regulator completely, what exactly are you referring to? The black knob on the front needs to be turned all the way to the left before opening the tank?
Yes!

[jmhart]

This backwards jmhart!
While reading the gauges...
High side is closest to tank-on the left
Low side is output-on the right.

Oh yeah, right...I was thinking of a different reg. while I was typing.

[A. Nonymous]

The regulator on the tank is a Milwaukee MA957. It looks exactly like this one : http://cgi.ebay.com/Milwaukee-MA957-CO2-Regulator-Solenoid-Bubble-Counter_W0QQitemZ270231508136QQihZ017QQcategoryZ66 794QQssPageNameZWDVWQQrdZ1QQcmdZViewItem