View Full Version : Why do tanks crash?

06-20-2011, 06:55 PM
If you have ever suffered a full or partial tank crash, what caused it? Alternatively, if you have never suffered a major tank crash, is there any part of your system that could potentially cause one in the future?

06-20-2011, 08:34 PM
My tank crashed due to a design flaw, which led to an electrical failure, which led to equipment failure, which led to a temperature deviation, which led to low oxygen levels, which led to a water chemistry change, which led to disease and parasites, LOL. Seriously though, in my experience it tends to be a cascading series of unfortunate events which does stem from one or more points of origin. :cry: The sad part is, sometimes (or most of he time), it can be hard to pin point exactly where it all started to go down hill..

edit: wasn't referring to my current tanks BTW. Rather, previous tanks I've had. I've tried to learn from those past mistakes, and so far so good *knock on wood*

06-20-2011, 08:42 PM
No tank is bullet proof, any kind of equipment can fail at the right time to cause a fatal crash. I had a partial crash once due to a programming error in my controller logic which shut off the return pump over night. Almost had another one due to a damaged overhead power line.

06-20-2011, 09:25 PM
The issue that I ran into was a snail in my sump getting stuck in my return pump while on vacation.

Quite a bit of water had evaporated from the display and the temp was quite low by the time I got things fixed. No major losses but some of my coral frags browned out.

06-20-2011, 10:12 PM
Full on crash for me.... And full with capital letters.....caused by moving the tank

06-20-2011, 10:25 PM
Only crashes I've had are due to vacations and very capable people "looking after" the tank and being lazy. (not topping up sump and letting it run dry).

06-20-2011, 10:34 PM
I never had any crash ever no equippment,no heating,no electrical and no chemical problem in any of my tanks, i think simply because i take my time for everything.

Well once only due to house fire shorted wires in bathroom killed all fish (lack of oxigen) i voted to bullet proof so far crossing my fingers.

06-20-2011, 11:10 PM
I've had a couple of misfortunate happenings.

My last fresh water tank was shut down due to a heater malfunction. The heater stuck on and cooked the tank. While the loss was sad, this sent me looking for an aquarium controller which lead me down the salt path.

I had two flame wrasses die in my 90G from what I believe was shipping stress. (A good argument for QT). The problem was I couldn't get the dead fish out. The water quickly went bad. With a series of massive water changes and the careful use of Prime, I lost only my shrimp and brittle star. The rest of the tank survived but it was a very close call.

I had another near miss when my Tunze ATO pump decided to stop working while on vacation. The return chamber in the sump ran dry and the return pump ceased. The real problems started when the tank sitter found the problem. After replacing the return pump and restarting the ATO pump, the ATO proceeded to pump 5 gallons of Kalk saturated water (pH 12.4) into the tank. The pH in the tank quickly rose to over 11.

Heres where the controller saved me. I received an alert for high pH and figured out what had happened. The tank sitter returned to my home and slowly brought the pH back down with vinegar. No losses. Thanks Bryce.

My new tank has two controllers, two return pumps, two groups of heaters, two fans, two ATOs, two auto feeders, and two skimmers. All of the critical equipment is split across two separate electrical circuits. Each controller manages one set of the listed eauipment. I'd still say there are potential problems, but I've gone a long way towards reducing risk.

I asked the question just for fun and to see what other peoples experiences have been. I'm very happy to learn from other peoples mistakes - especially if it saves my tank. Anyways, the chiller poll had been up for long enough.

06-20-2011, 11:41 PM
Mine started when I purchased my Apex Controller. There was a problem with the sensitivity and it would constantly reset the EB8 so a heater became a chiller dosing pumps would run contsantly etc. etc. it would reset on randon days but always at midnight. so a lot of damage was done while I was sleeping. I finally went online with it and the rep from Neptune logged into my controller and fixed it up. It is a great controller and I've sworn by it ever since. I did lose almost all my SPS in the process, a bunch of inverts died, cyano outbreak to the point where I had to bake my rock to cure it. To make matters worst I transferred my fish to a tank without a controller, I had the temp set correctly in the holding tank with my Rena heater. That night the heater stuck on an I woke up with all my fish dead! Some of these I had for years, my large yellow Tang and Hippo Tang were the biggest dissappointment. The silver lining was my Maxima and Squamosa clams lived! Go figure. I'm a big fan of redundancy but I learned the hard way that it just takes a moment and it can happen to anyone.

06-21-2011, 03:19 AM
As they say - there are two types of reefer's ------those who have had their tank crash and those who haven't -----------------yet!

I have had too many different issues and things go wrong I couldn't list them all. (especially since I don't know some of the causes)

06-21-2011, 05:14 AM
As they say - there are two types of reefer's ------those who have had their tank crash and those who haven't -----------------yet!

I have had too many different issues and things go wrong I couldn't list them all. (especially since I don't know some of the causes)

... but the main thing is we're too stubborn to give up!

... and we're lucky to have wives who don't mind a little water on the floor!

06-21-2011, 06:22 AM
I had a full crash caused by a design flaw which led to electrical failure which led to no flow and low oxygen levels. I also had a nano crash when a heater got stuck.

06-21-2011, 05:41 PM
two partial crashes, one a SE bulb broke the outer casing and continued to work, irradiating one side of the tank with UV killing 3 fish and a multitude of corals.

Second crash was due to reefer stupidity (not listed, I selected temperature deviation): moving the tank at the end of the day (an all day move) and left the livestock on a cool concrete floor (it didn't feel all that cold at the time) while I took a dinner break. Then put the corals into the tank without matching the temperature. The colonies in the coolest water started to RTN and caused a cascade effect that took 2 weeks of massive waterchanges to get the ammonia down to an acceptable level where it wouldn't cause issues for the rest of the corals. I lost most of my larger colonies, didn't lose any fish though (they were in an insulated cooler).

06-21-2011, 05:47 PM
One partial crash: An electric fan fell apart and into the sump, which tripped the
GFCI. Fish & critters came out ok but lost many corals. Not entirely sure if the problem was the oil in the fan getting into the water or a good jolt before the breaker tripped; or maybe a combination of both.

06-27-2011, 08:36 PM
My tank crashed due to the recirculation pump (from the sump to the DT) failing overnight. The oxygen levels in the DT fell and all the fish died. I think most crashes happen as a result of equipment failure. Cheap equipment is more prone to failure. For instance, many opt for cheaper pumps, which fail as they have a big demand on them (running 24x7 for years at a time). Cheap heaters will get stuck on and cause overheating. Skimmers overflowing will empty out the sump, etc.. IMO, get the best equipment you can afford. After all, it is a life support system for your precious reeflife. Losing them can be a big shock too (always use a GFCI).

06-27-2011, 09:17 PM
I think the ideal thing to do is run a pair of smaller pumps. Or (if your system is small enough) run an eheim. i'd bet my life on one =)

06-27-2011, 10:18 PM
I agree, i lost all my coral and inverts when starting out due to a cheap heater sticking on. My advice to anyone starting out on a budget is that good used stuff is better than shiny new crap.

06-28-2011, 04:56 AM
been lucky so far but a controller is defiantly next on the list, the network camera only goes so far when im out of town..

06-28-2011, 01:47 PM
FULL CRASH!!! Front pane of my 55g completely blew out.

06-28-2011, 03:52 PM
Had a leathers vs. LPS chemical war which resulted in the LPS dead but otherwise no crashes. *knocks on tank stand* I've never had a single dead fish/invert cause problems which is nice, don't need to feel in a panic if that does happen, they pretty much just become food.

[edit] My skimmer pumped 2 gallons of water on the floor because I didn't tighten it properly one time, but luckily I only run it 12hrs on during the night so it didn't have a chance to really do much.

06-28-2011, 04:33 PM
major crash due to moving.... took longer than I thought

06-29-2011, 06:42 AM
So here’s how the numbers break down.

The first 4 questions were a group. There were 88 votes in this section:

My tank has suffered a full crash – 17%
My tank has suffered a partial crash – 32%
My tank has never crashed, but has potential issues – 37.5%
My tank is bullet proof – 13.5%
It’s almost a 50/50 split between those who have had a crash and those who haven’t.

The next category was intended to identify why tanks crash. It was hard to phrase these causes as I didn’t want the poll to be too long. Regardless, there is some good information that came back.

The major causes of tank crashes (for those who voted) are:

#1 (16 votes) - Equipment Failure
#2 (12 votes) – Disease or parasites
#3 (11 votes) – Electrical Failure
#4 (10 votes) – Temperature deviationWater Chemistry had the second most votes at (13) but I am disqualifying the response as it seems that this is the end result from almost all failures and not specifically a root cause.

Each person will learn their own lessons from these statistics. For me, the results tell a number of things.

Most crashes are avoidable. Perhaps not all of them, but the more aspects of your system that you control and monitor, the less likely a crash will occur.
Controllers are really an essential part of any complex reef system. The trick is to use the controller to monitor and alert on critical system failures, not to respond to them. Responding to a false alert (false positive) can quickly lead to a real crash. It is better to keep the reef keeper in the process.
Buying good quality hardware is probably worth the expense or worth searching for something used.
Redundancy is important. Two is usually better than one.
Quarantine really is an important part of this hobby. Those who don’t quarantine risk losing everything.
Split essential components across multiple electrical circuits. Ensure that you tank won’t crash if a breaker is tripped.
Blackouts (Power Failures) do occur. Have some kind of strategy for eventually dealing with this.
All heaters are untrustworthy. A secondary temperature controller is essential.
Temperature needs to be controlled both up and down as it deviates from the ambient room temperature. Heat waves are scary things.

No doubt the list goes on and on. Perhaps the point is simply to weigh the risks associated with every aspect of your system. There were quite a few people (myself included) that indicated they were aware of a potential flaw but hadn’t fixed it yet. These are calculated risks.

I don’t actually believe that a tank can be “bullet proof”. Every aspect of my system is redundant, but I can still imagine a dozen scenarios that would lead to a crash. It could be as simple as knocking a food container into the tank.

It seems that once something goes wrong, there is a cascade effect ultimately leading to bad water. It’s important to have a plan for detecting and responding to the initial failure before it is too late. For example, when I dumped half of a reactor filled with Kalkwasser into my tank, the pH shot up to around 11.5 – I was able to bring the pH back down using Vinegar. I did not lose anything. Had I tried to solve this problem with water changes, I probably would have lost the tank.

Another interesting question might have been - How many people come back to the hobby after a full tank crash?

Presumably, these aren't the people hanging out on Canreef, but my guess is that many a good reef keeper is lost to a tank crash.

Anyways, an interesting question and interesting results. Thanks for the discussion.

- Brad

11-28-2011, 06:00 PM
Our 180g crashed when we had it several years ago because one of the critters died and released toxins.

We thought "The Thing" was cool when we saw it at the lfs and were thrilled and agog to have it - whatever it was. It was orange, about 1.5' long, hollow, and looked like some kind of wierd and wonderful worm - or something. Needless to say, because we didn't have a clue what it was, we were hoping it would filter-feed itself with the food we fed the fish. Don't actually know if it ever ate, even though we watched it during feeding times. It didn't have a mouth that we could see so how could we tell?

So, one morning at feeding time, I noticed dead and dying fish and pretty much panicked. Looked all over for electrical and other problems, but there weren't any. Then it dawned on me that the orange thing was missing. Yes, it had probably died and its toxins were killing our fish. Luckily I had a whole bunch of RO water in storage containers and quickly whipped up NSW. A few large water changes later, our fish had stopped dying, but we pulled quite a few dead ones out. We were devastated, to say the least.


- NEVER impulse buy ANYTHING for a reef or FOWLR.
- Remember that Google is your friend, so research the living heck out of anything you see at a lfs or online BEFORE bringing it home.
- Ask questions after doing research to clarify anything you have even the slightest concerns about.
- After research and asking questions, NEVER buy anything that you think won't fully thrive in your tank.

11-28-2011, 08:06 PM
Partial crash due to moving a 75 into a 150 and not having enough new water. By the time iI sorted it all out, I thought I was good, but woke up in the morning to a house smelling like dead acropora! Milky white tank, and downhill from there.

11-28-2011, 09:07 PM
I didn't add to the poll, as I don't think I qualify for anything listed, but can say there can be other issues besides crashes.

I haven't really ever experienced a crash, but I have experienced my fair share of problems. Most prominent was the loss of most of my SPS. Can't ever tell you why or how, it just happened, and it has been over a year, maybe 2 of this garbage... But now SPS is growing, I wouldn't say thriving, but growing and seeing positive things that were not there before.

And what have I done, really nothing. Gone back to the KISS method (Keep It Simple Stupid)... No more pellets, no more carbon, no more fany stuff like Zeo... Just a back refuge full of live rock rubble, then through a skimmer, then through some cheato. And oh, yeah some filter socks. Nothing more!

11-28-2011, 09:35 PM
It's all about the KISS I agree 100%.

I'm noticing a lot of corals and especially my acans look better in a big tank with relatively new water. I suspect a lot of our issues are due to years of a system running depleting stuff we never replenish to the same extent.

I did a few very large water changes on my last tank and I do believe there's real value in doing so as you sorta do a hard reset on these things.

11-28-2011, 09:48 PM
I suspect a lot of our issues are due to years of a system running depleting stuff we never replenish to the same extent.

I did a few very large water changes on my last tank and I do believe there's real value in doing so as you sorta do a hard reset on these things.

Brett, good point. I do a 50g change every other week, and I credit that with a lot of my current success.

11-28-2011, 10:21 PM
Brett, good point. I do a 50g change every other week, and I credit that with a lot of my current success.

I can vouch for this now been doing 45 gallons or so every week and have never had better colours or growth. Consistency is a big one also been dosing the zeo religiously now on a strict routine and wow the colours. :surprise:

11-28-2011, 10:55 PM
Mine crashed due tank failure. Have no idea how it happened but when I got home my tank was all over the living room floor with the front glass shattered into a million pieces.

11-28-2011, 11:44 PM
More than a decade ago I had a tank crash from a faulty heater sticking in the ON setting. Cooked the tank at 98F. The only thing to survive was a Coral Banded Jerk...I mean Shrimp. I learned from that experience and now use two small heaters instead of one big one. Or in the case of my reef, no heater! :twised:

11-29-2011, 03:13 AM
had the sps crash and another choice should be "still no f'ing idea".