Why do most tanks crash?

[Just John]

Often see people saying that their tank crashed and they have started over. Obviously, there are multiple reasons why it could, but I am surprised by how many people have had to deal with this. Is there something in particular that usually causes it to happen?

 

[Nano sapiens]

If ever there was a question with a multitude of possible answers, this one is it!

You could start a poll listing say 10 or so reasons why a tank was shut down. Would at least be an indication of what the main causes are.

 

[Azedenkae]

Often see people saying that their tank crashed and they have started over. Obviously, there are multiple reasons why it could, but I am surprised by how many people have had to deal with this. Is there something in particular that usually causes it to happen?

Usually it is a matter of probability, which basically is - even if something is unlikely to go wrong, it will always eventually happen if there's a chance of it happening. And unfortunately our systems are not exactly well-designed to prevent cascading effects if it does happen, though probably not to generalize too much, this would apply more to smaller than larger tanks.

Take my aquarium. It was running well for six months, and then my anemone got brown jelly disease, and then suddenly everything died. What changed? I added another light about two weeks prior. Highly doubt that was the case, because well, I have changed light settings a lot. But could be anything else. Maybe there was a particularly hot day that I was not aware of, and temperatures maybe rose too high for a few hours. Maybe a chemical I use was off. Maybe it had to do with my salt. Maybe the water was not filtered properly before mixing salt. Maybe some sort of organism finally grew enough in the aquarium to cause some sort of cascading issue. Maybe I was opening the window less and pH dropped too much one day. Maybe my corals depleted the water of nutrients and I was not feeding enough and they all started to stop doing well at once. Maybe a small organism got into the return pump and got completely smashed apart and released something. Maybe the corals decided to start finally warring.

The problem is that our tanks are not static structures, things change.

Unfortunately a lot of us may never know exactly what happened. For example, I have 0% idea if pH or temperature changed significantly for any period of time, given that I was not recording either constantly. There are equipment for that nowadays of course, but not everyone has it.

Could be some sort of trace element instead. Something could be consumed far faster than water changes was replenishing it. ICP tests would help, but again, not everyone does it.

Things like RODI filters or something 'stuffing up' is harder to figure out.

Of course with some detective work, eventually one might be able to determine what went wrong nonetheless, but the problem is that unless one has a lot of back ups and ways to mitigate problems, which is a lot of us, then yeah one day something could just happen and well, that's that.

I mean back to my example - my fish are 100% unfazed, so are my inverts. Yet suddenly all my corals died off at once. No algae bloom until after they died, so what gave? I did not change my routine at all over the past six months, but I can't imagine it being the light either. I figured it may be an issue with the filter for my water, but even then well, unless I was testing my water each time, then I still can't be 100% sure it was because my water that I used for a water change just before all my corals and anemones died that that is the culprit.

 

[Gtinnel]

About a year ago I had a tank crash and it killed all of my fish withing about 2 hours. I never did figure it out, but my best guess is that a bacterial bloom reduced the oxygen levels in the water.

 

[Bouncingsoul39]

From what I saw working in LFS the common causes are: over feeding, over stocking, not monitoring water parameters, user error with equipment, accidents involving some sort of chemical getting into the water (kids dumping detergent etc.). A lot of time when people say “oh, my tank crashed “ I just don’t believe them. What is more likely is that they just totally neglected the tank and everything died. If you want to call gross neglect a “crash” I suppose that works too.

 

[DaneGer21]

In my opinion, most tanks actually don’t crash.

 

[Just John]

Usually it is a matter of probability, which basically is - even if something is unlikely to go wrong, it will always eventually happen if there's a chance of it happening. And unfortunately our systems are not exactly well-designed to prevent cascading effects if it does happen, though probably not to generalize too much, this would apply more to smaller than larger tanks.

Take my aquarium. It was running well for six months, and then my anemone got brown jelly disease, and then suddenly everything died. What changed? I added another light about two weeks prior. Highly doubt that was the case, because well, I have changed light settings a lot. But could be anything else. Maybe there was a particularly hot day that I was not aware of, and temperatures maybe rose too high for a few hours. Maybe a chemical I use was off. Maybe it had to do with my salt. Maybe the water was not filtered properly before mixing salt. Maybe some sort of organism finally grew enough in the aquarium to cause some sort of cascading issue. Maybe I was opening the window less and pH dropped too much one day. Maybe my corals depleted the water of nutrients and I was not feeding enough and they all started to stop doing well at once. Maybe a small organism got into the return pump and got completely smashed apart and released something. Maybe the corals decided to start finally warring.

The problem is that our tanks are not static structures, things change.

Unfortunately a lot of us may never know exactly what happened. For example, I have 0% idea if pH or temperature changed significantly for any period of time, given that I was not recording either constantly. There are equipment for that nowadays of course, but not everyone has it.

Could be some sort of trace element instead. Something could be consumed far faster than water changes was replenishing it. ICP tests would help, but again, not everyone does it.

Things like RODI filters or something 'stuffing up' is harder to figure out.

Of course with some detective work, eventually one might be able to determine what went wrong nonetheless, but the problem is that unless one has a lot of back ups and ways to mitigate problems, which is a lot of us, then yeah one day something could just happen and well, that's that.

I mean back to my example - my fish are 100% unfazed, so are my inverts. Yet suddenly all my corals died off at once. No algae bloom until after they died, so what gave? I did not change my routine at all over the past six months, but I can't imagine it being the light either. I figured it may be an issue with the filter for my water, but even then well, unless I was testing my water each time, then I still can't be 100% sure it was because my water that I used for a water change just before all my corals and anemones died that that is the culprit.

Wow! That was a lot of effort - Thanks!

 

[Ef4life]

A friend had a tank crash this week. Not sure what happened. Edit - fish loss and angry corals.

but in talking with her I mentioned how icp and the biometrics tests now available could be great to have on the shelf ready to use for situations like this. It wouldn’t save your tank, but knowing what was in the water during the crash might give a lot of insight and information that we have never had access to in the past. Of course this would also require semi regular icp tests a few times per year to know of patterns and changes to get the most benefit

 

[MaxTremors]

The only tank crash I’ve ever had in 20+ years of reefing is when I was on vacation and my house/tank sitter didn’t notice there were obvious problems with the tank (return and circulation pumps stopped working). I’ve had tons problems over the years, but nothing that has completely crashed my tank or killed everything.

 

[Tamberav]

A true crash… like sudden death.. seems be usually caused by a failed piece of equipment. Say a doser dumping in a gallon of alk or you are on vacation and the AC breaks and the tank gets to 98 degrees or a stuck heater.

A natural event like the freeze in Texas that killed and froze solid many tanks. Others lose theirs to hurricanes because they have to evacuate and there is an extended outage.

Another example is the a tank failure like a panel blowing out.

Particularly virulent Velvet could probably be considered a crash as some people have lost entire tanks of fish in 48 hours.

It’s an ecosystem being powered and ran by devices that can fail. Some are more reliable than others and Mother Nature also has a say.

 

[Spieg]

Heater failure has got to be one of the more common causes.

 

[MNFish]

It seems to me a lot of crashes happen around the time people think everything is going great. From what I have read some of the more popular reasons are
Heater malfunctions

Ato malfunctions or other malfunction that affects salinity

Doser malfunctions

Ro filter malfunctions

Drinking while doing tank maintenance and doing something dumb

Something getting added by mistake

Power outage

Or a lotof times people start letting the routine stop, seems like a lot of people hit a wall and kind of give up after awhile.

If you are in long enough something will malfunction, however they have way better ways of monitoring for failures now days so hopefully equipment driven tank crashes will become less and less.

 

[Jedi1199]

Drinking while doing tank maintenance

Uh oh...

 

[HB AL]

Often see people saying that their tank crashed and they have started over. Obviously, there are multiple reasons why it could, but I am surprised by how many people have had to deal with this. Is there something in particular that usually causes it to happen?

I have never had a tank crash in 35+ years. Nowadays it seems if you have Aiptasia or some cyano or algae people call it a tank crash and do a full reset?@@&#%*÷=<

 

[74rus]

some time tank crashes for its own reason, most of the times human error.

I had a tank “crash” 2 years ago. Moved from 90 to 120 , 90% of coral and fish died within a week ,for some reason got huge ammonia spike right after the move. Used all the rock , sand from original tank, didn’t add anything new.

 

[MNFish]

Uh oh...

I wonder if that was how vodka dosing was figured out....

 

[Adolfo]

some time tank crashes for its own reason, most of the times human error.

I had a tank “crash” 2 years ago. Moved from 90 to 120 , 90% of coral and fish died within a week ,for some reason got huge ammonia spike right after the move. Used all the rock , sand from original tank, didn’t add anything new.

Reusing the sand could cause the ammonia spike

 

[KrisReef]

Too many stop lights causes a lot of problems.

 

[74rus]

Reusing the sand could cause the ammonia spike

If knew that before the move, I would’ve saved myself time and money.

 

[Jedi1199]

Reusing the sand could cause the ammonia spike

A very good reason to have good sand movers in your tank... I vacuum my sandbed once a month. Give it a bit of a stir on my weekly water changes...

My 180, which is too deep to reach easily with the gravel vac, fortunately doesn't need my help. The triggerfish I have does an extremely efficient job of reorganizing the sand to his own preference lol... I smooth it out once in a while just to keep him busy.