What happened?

Alright here goes the whole sad story.

Started my tank with sea water and live rock. Added fish very slowly, and had a good tank running with fish, rock, shrimp etc. for quite a few months. Nice and stable....

Now comes the horrible part:

I did a water change with sea water that I had collected 3 or 4 weeks previously. I have about a 80 gal tank. I changed about 20 gals. And then things started to go seriously wrong, seriously fast. The fish started to hide, and act strangely. It was on the week-end, after hours. I watched them get worse and worse, and watched the water turn brown in colour. At 3 am I had to drive to the beach to get fresh water. I could catch the fish in my hand as I transferred them to fresh water they were so far gone. I didn't bother about niceties like temperature acclimatisation, I got them out of there asap.

Well, I didn't lose as many as I feared. The shrimp died like the energiser bunny when it's batteries went flat. They just sort of stopped moving. I lost a sergeant major (I'd caught it on a hook from the sea) and a rusty angel. Losing the angel and shrimp really hurt, because I'd often watch the shrimp clean the angel. Not to mention the feelings of extreme guilt as well.

The remaining fish went to the LFS, who kindly gave them temporary accommodation and they are now none the worse for wear (2 clowns and a domino). They're all back in the tank which has cycled nicely.

Of course when I tested for ammonia the levels were off the charts. I eventually had to do a 100% water change and start again. 80 gallons of water works the shoulders quite a bit!

Now the question is: what went wrong?

The drums that stored the water once upon a time did store hydrogen peroxide, and phosphoric acid. A LOOONG time ago. But when I initially stocked sea-water I used these drums with no ill effect. I had even done a top up with stored water before with no ill-effect. So, what happened:

a) Over time, chemicals leached into the sea-water and killed organisms in the sea-water and they polluted the water with ammonia and/or the chemicals, once in the tank, killed of the ammonia processing bacteria or

b) Regardless of the chemical issue / hypothesis, what happened is that over time natural organisms in the seawater died and polluted it with ammonia anyway.

Question: can seawater be stored in any container at all, and if so, how? I have been told that you should put sand in the drums if you wish to store seawater.

I have since purchased virgin drums to eliminate the chemical theory (which I don't think happened).

Keen to hear from the experts.....

 

You're not topping off for evaporation with salt water are you? Since you're using natural sea water, I'm wondering where do you live?

 

The only person I know who uses NSW filters all of it with a diatom filter to remove all plankton and parasites. The plankton will die in the storage can producing Ammonia and eventually high Nitrates. Then he keeps it aerated well and in the dark for up to a couple of weeks.

If he intends to use it immediately, he merely adjusts the temperature and salinity to match his tank and then he uses it.

Please note that he doesn't collect his water from anywhere near the shore.

 

Test stored water before adding to tank --- bet that is where trouble is coming from. -

 

I hate to hear that with the tank. Glad some of the inhabitants survived though.

I'd say your problem is either with the old drums (chemicals) or with die off in the stored water.

If you're collecting water from the beach I'd make sure you get out pretty far becasue the water close to the shore is polluted with who knows what not to mention the shore is a nitrate factory. All of that foam on the beach is the same thing a protein skimmer takes out of the water...

 

Thanks for your replies

I pretty much figure that I'll have to use the water straight away.....As for not collecting it at the beach - practicalities dictate how far out you can go....The ocean's a pretty big place and you get what you get. Testing the water yields no ammonia or nitrates at all. The scum on the sea I would guess indicates protein in the water, but there's not much of that either, or wasn't when I collected.

@amcarrig: Not topping up with sea water - RO water. I marked the level on the sump when originally filling the tank, and I add RO water to keep it there every day or two...I also monitor sg and keep it about 1.022 - 1.023
I live in Durban South Africa, and I'm about 10 miles from the nearest beach. twenty minutes and I'm filling my drums.

I guess that the lesson to be learned is that natural sea water will not keep. Go fetch it - use it, throw it away..I'm sure most of the forum has experienced the shock at watching things unfold and not being able to do much about it....

 

I'd just buy salt Seems like alot of work...

 

Not really

You got to keep fit somehow. And when I'm feeling lazy, there are plenty of people willing to fetch and carry for a fee

 

Anyhow - things seem to have settled. Ammonia is dropping, fish are happy....
I just miss the deep angel eyes and I feel so bad....

 

I'm terribly sorry for your loss. This hobby is NOT an easy one and it hurts all of us when disaster strikes. However, sharing your experience will help someone else not store NSW unless it has been filtered.

I know it doesn't help your emotions right now but your are saving someone else some similar sad emotions.