Recent multiple deaths in tank

Question
QUESTION: We have a 90 gallon saltwater tank and we have been doing well for a year.  Occasionally a fish would die but not anything to be alarmed over.  We even made it through hurricane Ike with no power for 6 days so I know filtration is not our problem.  Over the last 3 weeks almost all my fish have died all except for a sea hare, sea urchin, an anemone (only a week old) and some snails.  We lost tangs, blennies, damsels, angels, clownfish, crabs, and a goby.  The store has tested our water and all is fine.  I belive that maybe we have introduced something biological into the tank.  We have a rather dated setup but very adequate.  We do have a protein skimmer, uv filtration, 3 powerheads and a wavemaker.  I purchased a new heater as I was worried the old one might not work well.  We added some biological filter material about 2 weeks ago but it hasn't helped.  I bought 8 damsels on Sunday and all but 2 have died and it is only Tuesday.  I did read that activated carbon is not a good idea and my husband did place some in the system about a month ago.  We also introduced some live Fiji rock into the tank around the same time.  We are thinking of taking what we have back to the store and starting all over again.  Is this necessary or is there another alternative?

ANSWER: Hello Kristina,

I a m very sorry to hear about your losses and troubles.

I want you to know that although I believe you think you are doing things in 'stages' and slowly, (over a period of time), i think you are still doing thing too quickly.

Especially when things are not going well or like you think they should be.

Adding a half dozen damzels or more is just not prudent.  Sorry.  Although you think it might okay to have a fish die, 'occasionaly' I dont think that is acceptable.

Most of these fish have life spans inteh tens of years inthe wild.


BUT, the good news is, i think you might have given the answer to the problems.

The first problem is that you trust your fish store for testing the water, (and making recomendations that end up with you buying more stuff)...

Please buy some test kits.  Nitrate, Ammonia, and salinity.  (it doesnt sound like you have any corals at this time, so those test kits should be fine)

I am thinking that the addition of hte live rock a few weeks ago was the problem.  Anytime yo add or subtract live rock or live sand, you will have a 'cycle', and will end up producing a bit of Ammonia.  Ammonia is almost certain death...

As for what you should do now.  nothing.  Just keep testing the water, and watch the ammonia go down.

Do weekly large water changes, 30%, then slightly smaller then smaller until you get to your regular water change cycle of at least once a month (10-20%)

AFter the ammonia has gone away, and once your nitrates start to drop, then you can add no more then 2 fish at a time... then let hte bilogical filtration build up to handle the new bio load.. and repeat until you have all the fish you think you can handle...


Good luck, and let us know how things work out for you...


Mr. Bill



---------- FOLLOW-UP ----------

QUESTION: Thank you for the quick response.  I called the store where we have our water tested (last testing on 2/28/09) the results were:
Specific Gravity: 1.024
No ammonia
No Nitrites
Nitrates - 10
PH - 8.4
Alkalinity 200

Unfortunately I have been using conditioned tap water where I should have been using reverse osmosis water. I am going to call my mud district and find out what changes they have made in the water as that might be one problem.  The store recommends a Polyfilter to see what might be being absorbed to find some clues.  I do have all the test kits and run them periodically myself.  I have the store test my water whenever I lose a fish just to make sure I am not making any mistakes.  

I will also do the water changes as you recommend but this time I will use better quality water.  I surely do not intend on buying any more fish for awhile.

Answer
Hello,

That is great practice to have the store double check your results, as each test kit is slightly different as everyone might use them differently.

Im glad that the ammonia is not the problem, (although it might have been and already corrected itself).

A poly filter is good to try, although they are not that accurate in discerning 'quantities or levels' of the contamininates.

But it is a good effort.

You can buy an ro/di filter online from ebay, or through several other places.  I reccomend www.filtersdirect.com or www.bulkreefsupply.com

Most filters are the same, but, some distributors get better RO cartridges, (the heart of the system).  all cartridges are 'rated' and tested, if they meet or exceed the stamped specification, they go in one bin, if they are just below, they go into another bin, and if they are way below they go into the bargain basement bin.

Hopefully that will explain some of the reasons why the ro/di filters are different prices all over.


BUT, I seriously doubt it is the water you use to top off or mix salt water that is causing fish death.

But, i have been surprised before.

Please let me know how things turn out.


Mr. Bill