Massive Tank Disaster; Now what?

[FreshwaterJeff]

Originally Posted by TheMainer

Definitely need to figure out the problem before more fish are brought into the picture.

Absolutely - that's the plan. If I can't figure it out, I'm going to cough up the cash to buy a new regulator. I don't want this to happen again...

[Lonewolfblue]

Sorry to hear about the losses. As for the ph crash, that's now what caused the deaths. The dropping of ph due to CO2 isn't what kills the fish. It's the high CO2 levels that suffocate the fish. Here's something Tom Barr said in another forum....

Originally Posted by Plantbrain

If you think about salts, such as baking soda which is the common KH buffer, this will explain the fish issues.

CO2 is not a salt.

Baking soda is.

Fish osmoregulate their blood and internal organs.
They exchange CO2 all the time and take in O2.

CO2 can be an issue if it's so high that it can interfere with O2 exchange(eg high CO2/low O2).

High O2/high CO2 works fine and high O2 and low CO2 works well also.

pH................well, a lot is said, but little is tested............
I think too much is focused on that parameter and not enough of the specific types of salts and ions.

KH will drop in poorly run tanks or non CO2 planted tanks(this is fine in these tanks and expected). Plants will go after the KH if there is not enough CO2 for a given light and nutrient load.

So will algae.

Some bacteria can do this but it's not likely, some in more reductive high organic matter substrates may produce a small amount of HNO3 acid, a strong acid, will decompose KH also.

DIY is not suggested for larger tanks because it tougher to get enough CO2 gas production and to keep it steady. I managed to do a fair job on a 90 gallon tank for several years, but it was a lot of work truth be told and I hardly did much at all after going to a gas tank.
Best $ I ever spent on a planted tanks was buying a gas CO2 system.

Regards,
Tom Barr

[FreshwaterJeff]

Ok, that makes sense to me. Any advice on how to avoid the issue in the future?

Also, my fish weren't found gasping for air at the surface as I would have expected...they "looked" like they were just shocked at a moment in time (i.e., my plecos were still in their caves, etc.) Is this still consistent with suffocation?

[tropicalfish]

Hmm, I assume the CO2 mix went into the tank. Make sure you use checkvalves so tank water does not go in. Get another two liter bottle and run a tube from the CO2 mix bottle to the empty bottle, then a tube from the empty bottle to the checkvalve, then the tank's reactor or power head, filter,....

[FreshwaterJeff]

tropical -

I'm not running DIY CO2. This is pressurized CO2 out of a canister. And there are actually 2 check valves on my line...

[Lonewolfblue]

Originally Posted by tropicalfish

Hmm, I assume the CO2 mix went into the tank. Make sure you use checkvalves so tank water does not go in. Get another two liter bottle and run a tube from the CO2 mix bottle to the empty bottle, then a tube from the empty bottle to the checkvalve, then the tank's reactor or power head, filter,....

I believe he's using a CO2 bottle, so there's no mixtures involved.

As for the regulator, etc, are you able to adjust the needle valve? Is it the Milwaukee? I can't remember. If it is, turn everything off. Then first, open the main bottle valve. This should give pressure in the main guage. Then slowly open the big black valve on the regulator, and turn it til the pressure is around 10psi in the 2nd guage. Once this is done, then you can slowly open the needle valve to get the correct setting. When doing this, let me know if it works, and if not, where exactly does it fail. You should be able to tell which step isn't working correctly.

[FreshwaterJeff]

Yeah - I've got the MA957.

I'm going to go through the trouble-shooting tomorrow and see if I can figure it out. I'm hypothesizing that it's my needle valve that's malfunctioning. We'll see...

[Lonewolfblue]

It could be that it's not properly seated, and may need a few adjustments for it to pop into place.When you close the needle valve, does the CO2 stop? If it does, then it's working properly. If something goes wrong with it, then you won't be able to shut the CO2 off, it will bubble with it feeling like it's completely closed.

[Lonewolfblue]

Another thing to add, could be end of tank dump if you had a leak somewhere. When I put my 10lb bottle on the 75G, it went to end of tank dump in 6 days. When I got a new bottle (they don't fill them where I get mine, but exchange the bottle for a full one), I re-set up the new bottle, and used Windex to spray all connections, and found I had a bad leak. I then closed all valves, removed the regulator and tightened up the loose connection with a wrench, and put the regulator back on the bottle, opened the valve, and made sure there was no leaks there, and turned it all back on. So it's not impossible to go to end of tank dump in a couple days. Check every connection for leaks.

[bigfoot150]

^I concur with checking for leaks. That is definitely important. Reading over the many posts here has me thinking but first i have a question. Do you have a solenoid hooked up to a PH meter or do you have a solenoid set to turn off pressure when the lights go out?

If so, the problem may be that water seeped back into your CO2 system and possibly into your regulator causing a malfunction. This would also explain why your bubble counter was empty. When i mentioned in my first post that i had a similar problem i was using the regulator by itself and no needle valve. I learned pretty quick that the regulator is a coarse adjustment and can change or open wider than expected.