Reef nutrition

PSA An Anatomy of a Tank Crash

Bruce Spiegelman

Sponsorship, Public Relations
BOD
Alternate title: We're always just one step away from reef Armageddon.

So -- my 120 gallon LPS tank crashed last week. I woke up in the morning to a tank that wasn't just cloudy -- it was nearly opaque. I'm detailing this so hopefully it will keep it from happening to someone else or if it does they can recognize the symptoms faster and minimize the issue.

Here's what I observed that morning, Cloudy water, decaying reef smell, all the corals closed up (and I mean all of them), dead invertebrates littered the sand which was covered with grayish detritus. All of the Trochus snails and Turbos were dead. Strangely enough the Nassarius were mostly fine. Brittle stars (dozens of them littered the sand as well.

About half the rock flower Nems were dead or missing. The two BTA's in the tank also dead. All three large leather corals were dead as well. The corals near the top of the tank were hit the hardest. Euphyllia at the top was dead, but those near the middle and bottom were closed up but still had some life.

All of the fish were fine although a little less "perky" than usual.

Test showed nitrates and phosphates were high (but not at a killing level). I attribute this to the die-off on inverts and corals. Alkalinity was at 10.3 although I keep it at 8.5-9.0. In an LPS tank it was doubtful that was the problem, but I considered it.,

Other things I considered and had recently changed/added. I had done a water change the night before. So I thought perhaps it was a bad batch of sale (IO), but I had used the same batch on another tanks water change as well so that was doubtful. I had put in two new bags of Chemipure, but a little research and experience pretty much ruled that out.

The only significant change I had made was adding a titanium ground plug in. After a lot of research I came to the conclusion that a simple ground plug could not have been a factor.

However, the reason I had added the ground plug was because for about 6 months I had noticed a little stray voltage in the tank. It wasn't effecting anything so I didn't really worry about. Again research -- a little stray voltage can be normal because of our equipment and a little bit doesn't effect corals. If it's too much some fish with a "sensitive' lateral line might show behavioral issues, but I hadn't seen anything at all for at least half a year.

Besides -- I was sure I knew where it was coming from and it wasn't actually inside the tank. When I noticed stray voltage (a small tingling in my fingertips) I just moved the Kessil cords a touch and it went away. I have four Kessils' daisy chained together and assumed it was a connection issue, but since it seemingly wasn't in a cord in the water (just at the top rear of the tank) and because a little jiggling cured it I ignored it.

Turns out I didn't delve deep enough into the issue even though (as Mike told me) usually stray voltage issues come from pumps or heaters -- you know the submerged stuff. I have regularly cleaned and maintained my pumps but regularly meant about once every 6-9 months because they are a bit of a pain in an AIO to reach and pull out (because of the cords.)

After numerous water changes the tank cloudiness dissipated, but not all the way. Corals were still closed up a week later. One fish had dies.

And so I grabbed a ladder and reached down to check the pumps. And a cord on the oldest of them completely separated with almost no force at all. Just a touch. Sure enough that cord was intertwined with the Kessil cords in the back and moving one moved the other.

Lessons learned -- maintain the corded equipment much more often. Don't just assume the issue lays elsewhere. I ignored it because I was "sure" it was the Kessils and because it had been there so long but wasn't effecting anything. The tank was healthy and growing nicely. I added the titanium ground just to be safe even though I thought it wasn't really a tank issue. I should have delved further.

So -- it wasn't a total crash. Over the next few weeks I'll have a better idea of losses, but this was not only a good learning opportunity, but also a good excuse to buy more corals. :)

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That's primarily why I am against the use of grounding rods for the tank, they mask problems.

Once you felt the "tingle" you should have rolled with it while you or someone disconnected every electrical device until the tingle stopped, then plug the other things back in just to make sure there wasn't more than one loose wire. While some might argue you're "playing with fire" (electricity) by using your body as a multimeter, and to an extend that's true the fact is you're not submerging your arms, and there's a better path for most of the electricity to take which is through the pump, and unless you're in wet feet on a concrete floor chances are you'll be fine. I often call this "the hangnail method of aquarium electrical diagnosis" because it just takes a little tear/cut/etc (often hang nail you yank will do it) and it really gives you a sensation if something is wrong.
 
Oh Bruce, this is such awful news. You are right that it could happen to any of us, apparently out of nowhere.

If you need any help with anything, I’m nearby, just let me know.

So if this broken wire is the culprit, with the amperage involved to cause that kind of destruction overnight, wouldn’t it have tripped a GFCI?
 
That's rough. I'm glad you tracked the problem down so it doesn't continue to be an issue.

I'm paranoid about stray voltage. I used to work in a shop in the Sacramento area. I was hired to help fix their coral tanks (I used to get dying corals for dirt cheap or free and get them to completely recover, I had several scoly I bought for $40). One of the first things I noticed on my first day at the shop was a huge amount of stray voltage and it was coming from a cheap Chinese powered that had frayed wires. Between that and bringing the magnesium up from 850, the corals stopped dying.

Since then, I'm very conscious of stray voltage. I actually use my multimeter to check the tank once a month and keep a log in my apex notes. It's one of the only things I like about the ecotech pumps, I never have to worry about them leaking voltage. I have had a Rio and a maxijett pump put voltage into the tank in the last 9 months.

Anyhow, let me know if I can help at all.
 
Reason most my gear are DC , 24v is less painful than 110. All pumps are on gfci sockets. That sucks.


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Dang, that really sucks. Sympathies!

I am glad you figured out what was wrong though.
Many crashes you never do figure out a root cause.

I am a bit surprised the GFCI did not trip.
But if both wires pull out, current flows from hot to neutral as normal, so no imbalance, so no trip.

That is one of the reasons to put in a grounding wire. It usually makes problems like that trip breakers easier.

That would be a good and very simple feature to add to an apex or other controller.
Grounding wire with current detection to trigger an alarm.
 
Dang, that really sucks. Sympathies!

I am glad you figured out what was wrong though.
Many crashes you never do figure out a root cause.

I am a bit surprised the GFCI did not trip.
But if both wires pull out, current flows from hot to neutral as normal, so no imbalance, so no trip.

That is one of the reasons to put in a grounding wire. It usually makes problems like that trip breakers easier.

That would be a good and very simple feature to add to an apex or other controller.
Grounding wire with current detection to trigger an alarm.

Apex does have the ability to alarm and shut down a device pulling too much current, as this would have. But one more thing to setup and deal with.

I’m wondering if maybe the wire defect was causing standing voltage but with nowhere to go, not enough current to hurt anything, then when you placed the ground plug it caused the circuit to close, and the current to skyrocket through the tank and that caused the casualties? I’ve heard it discussed that that is one of the downsides of using them.
 
A GFCI will trip with only about 5 milli-Amps of current. Tiny.
It trips when the hot and neutral do not match, not simply when the hot wire has lots of current.
Apex cannot detect that imbalance, it only checks overall current levels.

If you have exposed neutral (white) wire and no ground:
No big deal, no current flows.

If you have exposed hot (black) wire and no ground:
If tank is well insulated, which it usually is, there is no place for current to go.
So actually it is somewhat safe, until you put your fingers in.

If you have exposed hot wire and exposed neutral wire, and no ground:
It shorts out through the water, but just directly from the hot wire to the neutral wire.
So very localized current. a GFCI will NOT trip in this case. No imbalance.

If you have exposed hot wire and a separate good ground:
This is where you get real dangerous current through your tank.
However, this is also where the GFCI trips right away. Or should.

My opinion: You probably have a bad GFCI.
They can go bad. 2% or so. Test them!
They can also be hooked up incorrectly. (Testing with button will not help on that)

So when you added the ground, it should have tripped, but did not, so you had current in the tank.
 
If you have exposed hot wire and exposed neutral wire, and no ground:
It shorts out through the water, but just directly from the hot wire to the neutral wire.
See I dunno about that, the resistivity of copper is almost 10 million times less than sea water, so the current is still more likely to go through whole circuit with very little bleed over due to the exposed nature of the wires.

Don't get me wrong the resistivity of sea water is absolutely tiny when compared to air, but when compared to actual conductors it's huge. One of the reasons why you feel a bit of a tingle in the tank, yeah some of it does go through the tank water but it's very small in comparison to what goes through the pump. As a result yeah, the Apex won't detect that.

Personally I'd wonder about the contamination of the water due to all the junk inside the pump more so than I would about electrical current going through the tank.
 
Oomph, sorry about your loss. I'm in the boat that if you feel anything in the tank, it's time to figure out what's causing it versus delaying.
 
So sorry Bruce! However, you've probably just saved me from going down the same road. There is an occasional tingle from something in my 60gal cube, but I haven't been able to replicate it. I'm going to hunt it down!
 
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