Recirculating c02 scrubber fail

[Acroporaaddict]

Setup a recirculating c02 scrubber on my system a few weeks ago. Asked my wife to feed the tank some food as I didnt have time to do it before I left for work. I guess the skimmer started overflowing and now I have a closed loop running water from the collection cup, through the soda lime media and back into the skimmer input. Ph shot up and I can assume my kh did the same thing. Wont be home for a few hours, don't think I've stressed this much in a long long time...

 

[Durandal]

Bring the pH down ASAP with unflavored soda water or HCl until the pH is <=8.6.

This pH is really high, higher than what is achievable with a kalwasser overdose I think. Bad things may happen. I would act quickly.

The soda lime has sodium hydroxide in it.

 

[Acroporaaddict]

Bring the pH down ASAP with unflavored soda water or HCl until the pH is <=8.6.

This pH is really high, higher than what is achievable with a kalwasser overdose I think. Bad things may happen. I would act quickly.

The soda lime has sodium hydroxide in it.

Unfortunately I'm at work for another two hours and have a 45 minute drive home.

 

[Durandal]

Researching the composition of soda lime, it is mostly calcium oxide + a few % sodium hydroxide.

SO... if my understanding of the chemistry is correct, this should behave much like a kalkwasser overdose, but with a bit of sodium hydroxide thrown in. Is there precipitate in your tank water? Hopefully as in a kalkwasser overdose, precipitation of calcium carbonate has limited the impact of the event on your alkalinity and calcium levels. The extra sodium hydroxide in the mix may be what really screws the pooch, as without a stochiometric amount of a divalent cation to bring it out of solution as with the calcium oxide, I don't think there is any limit to it's ability to drive up tank pH/alkalinity levels.

You may need to adjust the alkalinity down with HCl.... advice from #Randy Holmes-Farley would be the best thing you could get right now.

If your soda lime is like mine it probably has a water soluble indicator dye in it, so you should probably run some carbon as well. Another thought, soda lime gets hot as tick when you flood it with water, so you might check that you don't have compromised reactor.

 

[Durandal]

Is water still running over the soda lime? If so, get your wife to take drastic action to stop it before the situation worsens. Be careful hydrated soda lime slurry is caustic as hell. There is allot of hydroxide in your scrubber bed, and it won't likely dissolve all at once as a precipitate of calcium carbonante will slow it down. Surely she can at least disable the pump?

Anything you can do to increase aeration remotely through your apex(increase flow, etc) will drive CO2 into your water....helping some.

As an act of desperation, you might try bringing your alk down remotely by running your calcium dosing pump via apex to help precipitate the excess alkalinity. Since you don't know what this event has done to your Ca++ levels, and you are in uncharted territory with a mixture of calcium oxide and sodium hydroxide, I would consider this a very risky move. In theory it might help, but I take no responsibility if it doesn't or in fact makes your situation worse. It is dosing blind.

If you find that your calcium and alk levels are in fact lower then before the event, then your tank chemistry is behaving like this is a two-part/kalkwasser overdose and the correct action is to aerate well, bring the pH below 8.6 with acid, and continue dosing calcium and alkalinity to help keep then from drooping like a stone. Balanced overdoses at high pH cause rapid precipitation of Ca++ and alk and this effect can be more damaging then the initial spike if you shut down all dosing.

If on the other hand your calcium is low and your alk is sky high(like >12), then your tank chemistry is responding to this event in a manner similar to a soda ash overdose, and you may need to correct your alk down with acid, aerate well, and support your calcium levels with calcium dosing.

My guess? It will behave like you have overdosed kalkwasser and the soda ash component of two-part at the same time.

My heart goes out to you. I saw the recirculator post the other day and was thinking about trying it out myself to save money on the lime....This could have been me.

 

[Acroporaaddict]

I turned the skimmer off remotely and had her remove the co2 scrubber. The skimmer is now back on providing aeration. I also have a air pump feeding outside air to the tank 24/7. She says the system looks good except the green slime is showing about 50% polyp extension. No sign of precipitation

 

[Durandal]

I think I would be most concerned at this point with getting the pH below 8.6 for the safety of everything in your tank, including your fish. Your pH is sky high for saltwater.

This is the definitive guide to lowering pH, by RHF:
http://reefkeeping.com/issues/2005-03/rhf/
"
Solutions to pH Problems

Some solutions to pH problems are peculiar to a specific cause, such as adding vinegar to limewater, or using less of it. Some general solutions, however, are frequently effective. My recommendations on how to deal with high pH problems are detailed below.

The most benign way to reduce high pH is to aerate the water more. Whether the aquarium looks well-aerated or not, if the pH is above 8.5 and the alkalinity is not above 4 meq/L, then the aquarium is not fully equilibrated with carbon dioxide in the air. Equilibrating carbon dioxide can be much more difficult than equilibrating oxygen. Air contains very little carbon dioxide (about 350 ppm) relative to oxygen (210,000 ppm). Consequently, a lot more air needs to be driven through the water to introduce the same amount of carbon dioxide as oxygen. Perfect aeration will solve nearly any high pH problem, and will rarely cause any problem of its own.

That said, sufficient aeration is not always easily attained, and other methods can be useful. These other methods are:

A. Direct addition of carbon dioxide. Bottled soda water (seltzer) can be used to instantly reduce aquarium pH. Be sure to select unflavored soda water, and check the ingredients to be sure it doesn't contain anything that should be avoided (phosphate, etc). Many manufacturers list water and carbon dioxide as the only ingredients.

I recommend adding 6 mL of soda water per gallon of tank water to reduce pH by about 0.3 units. Add it to a high flow area away from organisms (such as in a sump). The local pH where it first is added will be very low. Going about this procedure slowly is better than proceeding too fast. If you do not have a sump, add it especially slowly. Some soda water may have more, or less, carbon dioxide in it, and the lower the aquarium's alkalinity, the larger will be the pH drop. Also, the higher the pH, the smaller will be the pH drop, because the buffering of seawater declines steadily as the pH drops from about 9 to 7.5.

B. Direct addition of vinegar. Commercial distilled white vinegar (typically 5% acetic acid or "5% acidity") can be used to instantly reduce aquarium pH. Do not use wine vinegars as they may contain undesirable organics in addition to the acetic acid.

I recommend adding 1 mL of distilled white vinegar per gallon of tank water to initially reduce pH by about 0.3 units. Once again, add it to a high flow area away from organisms (such as in a sump). The local pH where it first is added will be very low. Going about this procedure slowly is better than proceeding too fast. If you do not have a sump, add it especially slowly. The lower the aquarium's alkalinity, the larger will be the pH drop. Also, the higher the pH, the smaller will be the pH drop, because the buffering of seawater declines steadily as the pH drops from about 9 to 7.5. Remember, there may be an additional, later drop in pH as the vinegar is metabolized to carbon dioxide.
"

Maybe get the wife to run to the store for seltzer?

The lack of precipitation is, unfortunately I think, a bad sign. It looks like precipitation is not removing the overdosed compounds from the water.

 

[Acroporaaddict]

I could just run co2 from my calcium reactor bottle directly into the sump correct? That way there is no salinity change from adding bottles of seltzer water and also no chance of bacterial bloom from basically carbon dosing with vinegar

 

[Durandal]

Actually, be careful, it would suck to overdose...

We should get a second opinion I think.

 

[Acroporaaddict]

Actually, be careful, it would suck to overdose...

We should get a second opinion I think.

Almost home. Thanks for all your help. I'll update the thread as things unfold

 

[Durandal]

If you decide to proceed, go slow with it... pure CO2 gas will pack a punch.

 

[Durandal]

I worry that RHF would have mentioned dropping in an air-stone hooked up to a CO2 regulator as an option if it was an option. Be careful.

We haven't spoken about it, but water changes will of course help with whatever water condition you encounter(don't know your size/ feasibility).

 

[Durandal]

I hope you have some two part salts in addition to your calcium reactor, because I strongly suspect you will need to add some calcium chloride.

 

[Acroporaaddict]

Alk jumped from 7.2 to 8.7

 

[Acroporaaddict]

Ca from 420 to 475

 

[Durandal]

OK, sounds like what you would see from a kalkwasser OD.

 

[Durandal]

I have to wonder if precipitation will commence once your pH returns to the land of the living. Make sure that as your pH drops that your alk doesn't overshoot to the downside.

It is probably a good thing that this appears to be behaving like a two-part/kalkwasser OD and not a massive overdose of sodium hydroxide!

 

[Acroporaaddict]

I'll retest alk and calcium once ph returns to normal levels. I wouldn't mind much if the alk drops down. I normally run it between 6.8 and 7.3 dkh. Having it at 8.7 worries me. Making some water right now for a 20% water change as well

 

[Acroporaaddict]

Ph is at 8.35, kh still at 8.7

 

[Acroporaaddict]

Contents of my co2 scrubber