Tank Journal Archive

IJG3145

Member
Oct 27, 2015
442
162
South Gippsland
A Stupid Mistake - The Accidental Dsb
I usually run about 5cm of substrate and because it can become a nutrient sink, I vacuum it when doing water changes and often stir it up with my hands too. I was doing this yesterday.

I wasn't paying attention while stirring up a reasonably rock free area, with my hand. I suddenly had the impression something didn't feel right but it was too late. What didn't feel right was the amount of substrate in my hand and to cut a long story short, over time sand had built up against the weir. The stink hit me straight away - a deep sand bed had formed in my tank and I had just stirred it up. I knew what had happened as soon as I smelt the rotten egg stench, I had released all sorts of toxins into the water column.

Totally stupid because I've warned others about this very thing happening to a well known reefer in MASA. :banghead

I run AC, Purigen and GFO but it wasn't enough. Overnight I lost most of most of my corals, in fact I've just taken a break to get away from it whilst I write this. At least I don't appear to have lost any fish.

The damage may not be over yet and in honesty I'm fairly philosophical about it....fete will have its way. Unfortunately though I lost 'Brian', my supersized brittlestar. Given his size and the years I've had him, it may have been just about his time anyway.

R.I.P. Brian
brittlestar 2016-03 a.jpg


Every hurdle is an opportunity so...

Over the next 3 months I'm going to actively try to reduce nutrients, which won't be easy given it has been a high nutrient tank for years. But it will give me a chance to experiment a bit and see if it can be done. If successful Resurrection #3 will be a low nutrient tank (goodbye gonis) and I might have a dabble in SPS, a new frontier for me.
 
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IJG3145

Member
Oct 27, 2015
442
162
South Gippsland
I threw an extra bag of purigen, an extra bag of AC and a small bag of Chemi-clean blue in, on top of my normal Purigen, AC & GFO.

Test results today are not good but way better than I hoped affter stirring up that DSB and having a lot of die off.
PH 8.1
SG 1.024
Temp 27c
Alk 6dKH
Ca 420
Mg 1200
NH3 0
NO3 10
PO4 0.15

I did a 25% water change yesterday and I'll do another one tomorrow. Looks like the only corals to survive will be a finger leather, morphs, rics & some zoas. There's still a blasto alive but it could go either way. Also lost CBS, peppys, a red seastar and of course Brian. I imagine my micro brittlestar population will be gone too.

Meantime I've removed a fair bit of substrate from the tank to minimise the chance of this happening again.
 

IJG3145

Member
Oct 27, 2015
442
162
South Gippsland
Sad to hear Ian - hopefully most things will survive.

Any reason you were running a 5cm sand depth?
Mainly because my stand is designed to hide the bottom 2cm of tank, so I have it set so just a bit of substrate is visible. Also to provide a greater environment for my substrate dwelling creatures such as Nassarius snails, Cucumbers, etc. I also like to observe the micro-fauna that populate the substrate over time although that's a minor consideration.

Also unlike most, I don't have a relatively flat sandbed. Mine tends to have peaks and gullys which are created by both the powerheads and some of the inhabitants, eg mylargest cucumber was about a foot long before it cloned itself and at that size, its pooh piles a pretty large.

Having said all that, I'm not committed to any particular depth so I would be interested to know how deep yourself and others run their substrate.

BTW a bare bottom tank isn't an option for me.
 

MagicJ

Moderator
Jul 11, 2011
9,650
3,761
Hobart, Tasmania
I like some sand from an aesthetic point of view, but I also don't want it to develop any anaerobic zones. I have not kept any wrasse for quite a few years, nor have I kept cucumbers. Nassarius snails don't appear to require any significant sand depth so I normally have mine around 2 cm.

I have bought a couple of bags of new sand for my tank so we will have to see how that turns out :)
 

IJG3145

Member
Oct 27, 2015
442
162
South Gippsland
A quick update.

I lost no fish and at least one of my two Tigertail sea cucumber clones is still alive.

I lost all anemone & shrimp.

I had a toxic green finger leather coral that had three distinctly separate clones on one small rock. One of the three died, one is hanging in there and one looks okay, so today I'll separate the two surviving ones in case I have to pull one later.

All other coral right down to palys were lost and I had some pretty flash zoas. Oh well.:(

The snails were interesting. Every snail in the tank (except the stromb) went belly up - literally. They were all lying there, upside down, with flesh exposed. Nothing moved including the stromb, all were non reactive even when probed with a toothpick BUT none seemed smelly. Now this makes no sense whatsoever, even to me, but for some reason I got it into my head to crank the heat up to 29. I then lined up all the snails I could find, along the front of the tank where I could observe them.

I really don't know why I did that or if it had any effect at all but once the tank had been at 29 for an hour or two, I saw my stromb move. Now Boris the Stromb is a cranky arse and usually if I pick it up it spikes me when it uses it's talon as leverage to move. It had not reacted before even when I probed it. I went to pick up a Trochus that I had previously checked and it was clinging to a small piece of rubble on the substrate. So now I know at least some of the snails survived.

The temperature may have been pure coincidence, perhaps the carbon, purigen, GFO, etc had finally made an impact on toxins, allowing some of the snails at least to recover. My son has the day off today so with his help I'll get a 2ft tank that I have in the workshop and set it up as a HT/QT tank in the lounge, then I'll begin serious inventory as I slowly acclimatise and move each critter to the HT. Then tear down and rebuild can seriously commence.

My goal is to have the main display redone, up, running and fully cycled & ready for stocking on Oct 1st. That will include a long cycle.
 

IJG3145

Member
Oct 27, 2015
442
162
South Gippsland
Update - all fish are ok. All corals and shrimp are dead. Total list of survivors is:
  • 3 trochus, 1 adult & 2 young out of a breeding colony of about 20
  • 1 turbo snail - out of dozens
  • 3 nassarius snails - out of 6
  • My single stromb snail
  • 1x black Sailfin Blenny
  • 2x PJ Cardinal
  • 2x Ocellaris clowns
  • 1x Royal dottyback
All surviving stock is in the QT/holding tank as shown below. All equipment has been sanitised. The GFO reactor is offline for cleaning but will go back tomorrow.