Complete Wipe Out On My Tank :(

[TigerIssey]

Sorry to hear abouut your losses, hope you come out the other side and continue with the marine bug.

 

[SkiFletch]

Ouch Gary, sorry about that, crashes are never fun

My guesses would be either O2 deprivation, or Ozone poisoning. Although if the corals come out and look OK, I'd say your problem was O2 deprivation. Ozone poisoning would probably kill the corals before the fish...

SkiFletch - could you please explain how O2 deprivation or Ozone poisoning occurs and wipes out a tank. This post is sad and scary. Are there any signs to look out for? I'm assuming this crash built up slowly without Gary realising. What's to stop it happening to anyone of us? Why do you think it may have happened?

Cheers

*Takes deep breath in*

Well, let's start with Ozone poisoning, since that one's easier . Gary has recently started using Ozone at very small doses to increase the effectiveness of his protein skimming. Ozone is an extremely reactive oxygen species which will attack and oxidize organics quickly, especially complex proteins and fats. The idea with using ozone is to inject it either into your drain line if you use a sump, or prefferably directly into the skimmer. There the Ozone reacts with dissolved organics in the water column, breaking them down into products that the protein skimmer can then remove (because skimmers really only remove about 30-40% of all dissolved organics, the rest are too complex). If the right amount of ozone is injected, it is all "used up" in breaking down the dissolved organics, and doesn't make it back into the water column. If the injection rate is too high, you can have free ozone sent to the display tank where it will begin directly oxidizing corals, algae, fish scales, fish internals, inverts, etc. Basically anything alive. And furthermore, if your injection rate is WAY too high, some can get into the ambient air around the tank and start oxidizing the reefkeeper's skin, lungs, etc.

It's exceptionally rare to ever get that high as most ozone units are way too undersized to go that far, but it's possible. In gary's case, since he didn't smell Ozone in the air (or at least I'm assuming he didn't cause he didn't say so), and since ONLY the fish were affected (ozone would harm any more-sensetive inverts/corals before it really killed fish), it is unlikely that O3 poisoning was the cause of death here.

Phew

Ok, next, O2 deprivation. First, we all must understand that Seawater is a very poor carrier of Oxygen. It has so much other "stuff" in it, there's just not as much room for dissolved O2 to fit. There is WAY more O2 in a liter of air than there is in a liter of Seawater. Knowing that, sticking a lot of fish, corals, and invertebrates which all consume Oxygen through metabolism into a small box filled with seawater has inherent risks. There are 2 common scenarios for O2 deprivation.

The first is a rapid change in pH. If the chemistry of the aquarium is such that alkalinity is very high, pH is high, calcium is low, and magnesium is low (compared to natural sea water NSW values), you can definitely get yourself into some trouble. In this situation, you can drive the chemistry towards supersaturation of bicarbonate (part of alkalinity). When bicarb is supersaturated without enough magnesium it will prefferentially react with calcium, making a salt of calcium carbonate which is not soluble at NSW pH. Since even though calcium is low compared to NSW, it is still higher than bicarb, you will have plenty available for the precipitation reaction (making CaCO3 salt). This precipitation reaction happens FAST, like minutes fast, and the water column becomes exceptionally cloudy. When it does, the pH crashes in the tank because pH is kept high by the artificially high bicarbonate. We're talking crash from say a high of 8.6 to 7.6 in minutes... Yikes.

When this happens, the fish, corals, and inverts all become stressed and start using more O2. Once the pH bottoms out though, the reaction fips back as Calcium Carbonate is now somewhat soluble in water. I forget the exact reaction equation, but somehow the reversal starts consuming O2 and CO2 at an alarming rate as the pH goes back up fast and the water remains really cloudy. Also here, often times aquarists will try to add a minor acid (vinegar) because they've read that doing so will eliminate the cloudiness. It will, but the released acetate (part of vinegar) is prefferentially gobbled up by bacteria native to the reef. But the using of that acetate by the bacteria ALSO uses Oxygen. So now you have O2 being used up in the pH swing, O2 being used by stressed organisms with increased metabolic rates, and bacteria gobbling it up because the aquarist reacted too quickly. The O2 levels plummet in the tank, and high-metabolism organisms like fish die first. Usually this type of event results in a FULL tank crash (fish and corals), but because this happened while Gary slept, he didn't add vinegar and compound the problem, so once the stressed fishes metabolisms stopped, there was enough O2 left for the corals/inverts and they survived. As far as prevention goes, first step is to increase gas exchange via surface agitation and prehaps an airstone and wait. Using Acids can work but you should use an Abiotic acid if you must (HCl, or H2SO4), even then I wouldn't reccomend using the acid unless you REALLY know what you're doing. MOST times, surface agitation and an airstone provides enough O2 and CO2 to slowly and safely correct the problem, provide enough O2, and lower the pH into a more reasonable range.

--------------

Second method, and more plausible in Garys case actually is an over-release of gametes into the water column at night. If a coral decides to spawn (and they almost always do at night), they release millions if not billions of gametes (like eggs and sperm) into the water column again in a matter of minutes. These gametes are very simple cells, not protected by much of anything which would be instantly and prefferentially attacked by the Ozone Gary was adding to the aquarium. They would also simultaneously increase the Oxidation Reduction Potential (ORP) which is the scale the Ozone controller measures, thus it wouldn't stop injecting Ozone. When the gametes are/were broken down, they are also usually littered with high-energy carbohydrates like acetate, glucose, etc. Then, just like above, bacteria native to the reef gobble up the high-energy carbon sources, using O2 to do so; O2 levels plummet fast, and the high-metabolic organisms like fish die first.

The preventatives for this mode of crash are somewhat more difficult. First, OVERSKIM like crazy. If the gametes can be removed from the water column before they're all attacked by the Ozone, then you avoid the problem. Second, don't use an ORP controller for Ozone injection. If you manually set a very slow rate of O3 injection, you can lessen the impact of such a difficulty. Remember, if the controller can't stick "on" you have less Ozone available to attack the gametes and you might just save yourself. Third, don't emulate moon cycles if you have a moderately sized aquarium. Usually the corals are stimulated by solar/lunar cycles as to when to spawn, so if you don't give that stimulation they won't spawn in the first place. If the aquarium is really large and has enough water volume to absorb some of these problems (say 150g and up), go nuts . Fourth, don't employ Ozone. Obviously if you don't use it, you're not at risk for this type of crash as it's Ozone dependent. Lastly, make as much surface agitation as possible, in both the display tank and the sump, this should hold true for EVERYBODY'S tank. Surface agitation increases gas echange in the water column and preferentially increases the rate at which Oxygen can go in the water, even if it's used up. It's like an In-Out thing, if there's more O2 going Out than there's going In, you're in trouble. And if you increase O2-In faster than it could ever be deprived through crazy surface agitation, you're safe from any O2 deprivation problem.


Phew, that was a lot of typing. If anybody actually reads all of that, you get a medal . Also, the final method I outlined (gamete destruction via Ozone) is more theory, not proven. I happen to agree with it, but you can take it or leave it. Although I didn't have samples of water from Gary's tank at specific times during the event to prove my theory, it all fits with his descriptions of what happened (overnight, no cloudiness, dead high-metabolic organisms). Gary, if you do read this far, I'd be curious to know if your skimmer produced more, less or the same amount of "gunk" during the crash. I'll try not bias you in which way I think it SHOULD have happened

 

[-Nemo-]

Thanks for that Ski, certainly worth the read. I agree with your theory, seems very plausible.

 

[TigerIssey]

Firstly, I would like my medal please.

Secondly, thank you very much for taking the time to explain all that not just Gary, to all of us, it certainly makes sense to me anyway.

Thirdly, if you are a one finger typist, you deserve a medal for typing all of that.

Thanks Ski

 

[SkiFletch]

Heh, no problem guys, I just hope as always that the knowledge is used to help somebody else, somewhere, eventually

And TI, I was taught to type by nuns who threw erasers at us and smacked us upside the head if we weren't fast or accurate enough, all with boxes covering our fingers so we couldn't see them. I can probably do about 40 words per min, maybe 50 if I'm being dictated to and I don't need to wait for my own feeble brain to catch up with my fingers

But I digress

 

[westiemarble]

WOW! Thanks for that Ski

 

[Trod]

Thanks Ski, that was extremely interesting and informative. and my god I actually understood it

 

[garybuk]

Heh, no problem guys, I just hope as always that the knowledge is used to help somebody else, somewhere, eventually

And TI, I was taught to type by nuns who threw erasers at us and smacked us upside the head if we weren't fast or accurate enough, all with boxes covering our fingers so we couldn't see them. I can probably do about 40 words per min, maybe 50 if I'm being dictated to and I don't need to wait for my own feeble brain to catch up with my fingers

But I digress

Hi thanks for that ski i tryed to understand it and most i did , my tank went very cloudy from the start and skimmer produced less from what it noraley did! i added an airstone stight away and moved all my power heads pointed to the water top. my redox (mv) went stight back up pretty fast! it has sence been running and my mv is all over at midd day is it reaches up too 200mv and later at night its heading back down to 80mv , iv been on holiday so my tank has been left for 3days and i came back to find it GREEN everyware is green with bubbles stuck to the live rock,sand,and glass im not sure if this is from the air stone running! also to note my ozone is not running over them 3days nor was my skimmer! but my corals are fine also my yellow watchman is still alive and my hermit crab ! if there is anythink eles you need to know or you wana help me with im greatfull !!!

 

[SkiFletch]

Well if you had the cloudy water, you likely had the pH paroblem, not so likely the gamete problem. The pH swings would have limited skimmate production at least initially, which hangs together too. Had you had the gamete problem I would have expected lower skimmate production at FIST, but followed by MASSIVE skimmate production.

As for the green algae, sounds like it might bye cyano or dinoflagellates. Likely from nutrients from secondary dieoff of microfauna and inverts, and a little of the fish decay that probably happened. Not running the skimmer while you were gone contributed for sure. Moving forward, I'd leave the tank fish-less for a little while longer, run that skimmer and Ozone and clean it up. Get a handle on your chemistry, especially magnesium, amybe perform a really BIG waterchange, and be patient for a few weeks. The system should settle down and the algae should control itself, once that happens you can consider adding some more fish.

 

[garybuk]

Well if you had the cloudy water, you likely had the pH paroblem, not so likely the gamete problem. The pH swings would have limited skimmate production at least initially, which hangs together too. Had you had the gamete problem I would have expected lower skimmate production at FIST, but followed by MASSIVE skimmate production.

As for the green algae, sounds like it might bye cyano or dinoflagellates. Likely from nutrients from secondary dieoff of microfauna and inverts, and a little of the fish decay that probably happened. Not running the skimmer while you were gone contributed for sure. Moving forward, I'd leave the tank fish-less for a little while longer, run that skimmer and Ozone and clean it up. Get a handle on your chemistry, especially magnesium, amybe perform a really BIG waterchange, and be patient for a few weeks. The system should settle down and the algae should control itself, once that happens you can consider adding some more fish.

Thanks ski , im hoping to get a new tank and starting all fresh with all new live rock too , so just leaving my tank as it is! one question tho! i have not been running my ozone but my mv levels are up and down like a yoyo??? any reason this? like right now its at 226mv??? i couldnt get it this high with the ozone running?

 

[SkiFletch]

Well, once you have a major dieoff event like this, your tank/rock's biology is really thrown out of whack. This has been poorly understood for a while now, but where before your tank was at somewhat of an equillibrium, now you're having mini stress and dieoff events likely in response to others. For example, some microfauna die and decompose, changing the ORP. Their remnants are removed from the water column and the ORP swings back down. But because they were pray for some other organism in the tank, their numbers dwindle too, and as they die/decompose, the ORP swings back up. There are so many equillibrium processes changing right now, it may take a while for things to settle down. Hope that made sense

 

[seffieuk]

Holy, Moly - Ski sitting at a typewitter with nuns throwing stuff at him what a picture that paints

But thanks, that was really interesting and informative and by the way - can I have a shinny new medal please

Seffie x

 

[ben1987]

Holy, Moly - Ski sitting at a typewitter with nuns throwing stuff at him what a picture that paints

 

[garybuk]

Well, once you have a major dieoff event like this, your tank/rock's biology is really thrown out of whack. This has been poorly understood for a while now, but where before your tank was at somewhat of an equillibrium, now you're having mini stress and dieoff events likely in response to others. For example, some microfauna die and decompose, changing the ORP. Their remnants are removed from the water column and the ORP swings back down. But because they were pray for some other organism in the tank, their numbers dwindle too, and as they die/decompose, the ORP swings back up. There are so many equillibrium processes changing right now, it may take a while for things to settle down. Hope that made sense

thanks again! check out my new thread and help me along lol

 

[Truck]

just out of curiosity, what does Ozone (O3) smell like?