View Full Version : Typical reasons for system crash

07/21/2017, 05:31 PM

What are the typical reasons for system crash? I finally got mine stable (I hope!) and want to find out what common mistakes people make to cause their system to crash.

Thanks for your input,


07/21/2017, 08:17 PM
Equipment failure is common.

Mike Ashton
07/21/2017, 08:33 PM
Disturbing an established sand-bed heater thermostat failure ammonia spike poor husbandry etc

07/22/2017, 05:23 AM
Accumulation of large quantities of waste, or sudden depletion of waste processing microfauna in the sandbed. The later usually being a result of introducing a microfauna predator such as sand sifting starfish and gobies etc.

07/22/2017, 12:23 PM
Neglect. Keep up with everything, including cleaning and inspecting equipment.

Smokey Stover
07/22/2017, 12:38 PM
Power failure Could come under Equip Failure. Hazmat Contamination, Aerosol Sprays, Air Fresheners, Cleaning products,( Wife adjusting to No Spray Zone lol) Hand Lotion, Sunscreen on skin immersed in tank, Oil or Grease, Degreasers on hands from working on autos/bikes. I really gotta watch that one....

07/23/2017, 01:28 PM
Assumption that you know what the cause is of whatever's going on. You can go a far piece down the wrong road if you don't test the things you don't think could be wrong as well as the ones you think might be.

07/24/2017, 10:52 AM
Sandbed for me, I replaced some really old Tunze pumps with Maxspect Grye pumps. They stirred my sandbed. Lost half my fish and most my corals. No more sand for me!

Sounds Fishy
07/25/2017, 08:07 AM
Allowing your bio load to out weigh your systems ability to process waste.Getting lazy,not doing water changes.There is a temptation (because people love their fish)to dose a variety chemicals to enhance your ability to control,water pollution, which can crash a tank,if not done correctly or in the wrong combinations.Simple,regular water changes is the best way to maintain a healthy system.

07/25/2017, 09:38 AM
Bad expectations.

Expecting small tanks to behave like large tanks (stability)
Expecting cheap equipment to last
Expecting non-redundant systems not to fail
Expecting to be able to outthink or out-equipment nature and bacteria
Expecting new equipment/methods to be better than tried and true stuff

Other than this, people change stuff way too much when they should just leave their tank alone.

07/25/2017, 09:29 PM
My imprecise 'accounting' of my own and others says equipment failure/malfunction is the primary cause. Whether stuck heater, run away ATO, power failures ..... some can be mitigated for, but spend enough time in the hobby and even the most meticulous of plans will be found wanting. For example, I recently had the full volume of my ATO reservoir added to my system over the course of one night - even though I run three redundant floats. How is that possible? Well, I run all my float switch wires through a common PVC conduit. An unnoticed dripping fixture was slowly filling said conduit which eventually made electrical connections on all those floats making apex think they were all closed. There's always a weak point.

08/02/2017, 04:51 AM
Bad expectations.

Other than this, people change stuff way too much when they should just leave their tank alone.

This! It's amazing what can happen when one tinkers too much and don't just let the system remain stable.

I'll also throw in bacteria and parasites.

Finally, an overly complicated system. I am always striving to minimize and simplify.

08/06/2017, 07:18 PM
Yeah, but tinkering is a big part of the fun of having a reef tank - at least it is to me. Just don't make material changes before going on holiday.

08/07/2017, 12:00 AM
Alk spike has crashed 2 of mine. Once it was CA reactor failure, once it was kalk/topoff failure. Other smaller spikes have done damage, but those were all out crashes.


09/02/2017, 07:26 PM
Jda said mine. Salinity swings on a small tank without an ato = sps coral crash.

I have heard of many people who had an ato that kept pumping and the shut off failed. Back up ato such as a tzune system is better than say a 50 dollar ato system with float valves only.

Also ball valves instead of true union valves can fail causing flooding, equipment and water parameter failures as well.

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