Can't keep fish

[butrfly253]

Hi, we have a 20 gallon reef tank. All of our corals, crabs, shrimp and snails are doing great. For some reason, we cannot keep any fish alive. The longest we have kept them is about a month. That was in the first few months. Now, we cannot keep a fish more than a week. The people at the fish store say there is nothing we can do. They said it is probably some kind of bacteria in the water and it is untreatable because any treatment will hurt the corals. Does anyone have any ideas? I would really love to have some fish. Thanks.

 

[scsinet]

Are you only buying fish from one place? It could be something you are doing but it doesn't make a lot of sense that your inverts are doing okay but not your fish...
Frankly, I've found that the wholesaler a dealer buys from can make a big difference. The closest LFS to me is who I deal with most. I have stopped buying fish from them. Every fish I buy from them dies. Inverts and corals, no problem. Dry goods, no problem. I suspect the wholesaler they buy from ends up with lots of cyanided fish.
What I'd do first, short of tearing down your tank, is an experiment. You should be doing this anyway, but obviously you are not, so now's a great time to start.
Set up a quarantine tank. Start with an empty 10 gallon aquarium and a small filter like a sponge filter, internal power filter, HOB filter, etc. Make sure all filter media is completely new, and all equipment is either new or completely dry (bacteria, pathogens, etc can't survive drying out). Put nothing at all in the tank,.. no substrate, decorations, etc. Also get yourself a bottle of Seachem Prime.
Either fill the tank halfway or so with purchased seawater or mix some yourself, using RODI water and either new buckets or a completely dry bucket that has never been used for anything except aquarium use. Make sure you age your mixed seawater at least 24 hours.
What you now have is a completely separate environment that has no chance of being exposed to your display tank conditions.
Buy a cheap fish from the LFS. Try a Damsel or a clown, etc but be sure it's something that you tried buying before that has died. Keep it in the QT for at least 6 weeks, adding a half capful of prime every few days to keep ammonia from building up, and changing water every week using seawater as described above.
If the fish lives for 6 weeks, put it in your DT. If he dies then, you know it's your system. If he dies in the QT, you can be pretty certain it's your LFS.

 

[lion_crazz]

How are you acclimating these fish? For how long?
What kinds of fish have you tried?

 

[butrfly253]

We buy fish from 2 different stores. We have tried clowns, damsels, gobies, cardinals, and blennies. We were told to acclimate the fish for about one hour by putting water from our tank into their bowl about everey 10-15 minutes. Thanks for your help.

 

[payton 350]

what type of corals...possible chemical warfare going on??

 

[scsinet]

Your acclimation method is not exactly the best way of doing it, but this is an acceptable method, so I'd imagine that you'd have better results than you have been....
The preferred method to acclimate is dripping. I'd go through it but I think there is an FAQ posted on it if you search for acclimation methods.
Hmmm
The first thing you need to do is post a complete set of water parameters.
Temperature: Min, Max, and Average for a given day.
PH
Ammonia
Nitrites
Nitrates
Calcium
Alkalinity
I can't image your water to be at fault with your inverts doing well, but we should check anyway. I am somewhat intrigued by what Payton said.. can you provide a livestock list?
Also, tell us about your lighting, your flow rates, and as much as you can about your filtration.
Finally, do your fish eat during the time they are alive? What is their behavior like up to the time they die? What is the average amount of time that fish are living? Minimum amount? Maximum?
Sorry for all the questions, but we could go on for days asking bits and pieces or get it all up front.

 

[lion_crazz]

I agree, we need to know all of this so that we know and understand your tank.
When you buy these fish, do you ever watch them eat at the LFS before you take them home?

 

[sleasia]

If you can post your parameters it will help them answer...20 gallons is a small tank, be sure your alkalinity is ok...also another frequent problem is that the lfs tend to keep fish in a lower salinity, not all of them but many do...before acclimating a fish be sure you check the bag water so you will have some idea of the salinity in which the fish has been kept previously....if it is very low say 1.017-1.020, and you plan to acclimate to a reef system with 1.025-1.026 this really should not be done over a period of 2-3 hours but should be done over a period of a few days...this is another reason why having a qt is important. you can adjust the qt to the salinity that the fish had been in in the lfs, and then after letting the fish adjust and recooperate from transport for a day, then slowly manipulate the salinity over a longer period of time to eventually match whatever your main tank is at....fish are much more sensitive to rises in salinity than to falls in salinity.

 

[butrfly253]

Thank you guys for all of your help. As of right now, the water is as follows:
Temp- varies between 81 and 83
PH- is about 8.5
Ammonia- between .5 and 1.0
Nitrites-0
Nitrates-0
Alkalinity-185
Salinity- 1.027
We are using a 24" coralife aqualight with a 65 watt actinic and a 65 watt 10000K compact fluorescent. We have 1 powerhead and have an aquaclear 70 with charcoal and ammonia pellets. While the fish are alive, they do eat. They seem to be very slow when they are alive. The longest we have been able to keep one alive is for about a month, and one only lasted about 2 days. As for the livestock, we have:
2 cleaner shrimp
1 hermit crab
1 anenome crab
1 sally-light foot crab
about 8 snails
and corals:
Fine Grape Coral
Frogspawn coral
greenstar polyps
a red open brain
bubble coral
chocolate mushrooms
fuzzygrass mushrooms
zoos
and pimple mushrooms
and 2 others I am not sure of (See Pic- Tree-like in middle and one on left side possible hammer coral?)
We do about 20% water changes every week or so.

 

[lion_crazz]

Well, the biggest problem with your tank and keeping fish is the ammonia level. Any ammonia present in the tank is dangerous. That alone will kill fish.

 

[sleasia]

I am assuming you have had the tank running for 6 months or so...and are you using r/o water or tap water? There should not be any ammonia. If there is, then the tank has not finished cycling, or something is dead, or for some reason your bio filter is inadequate. I would not put any more fish in for several months. In the mean time I would seed the tank with more bacteria, bio spira marine, and after a month or so run a uv sterilizer. by that time the bacteria should be established in the live rock and substrate and the uv will then help to kill any unwanted pathogenic bacteria and parasites in the water. I'm not sure if your salinity is a bit high...I would keep it at 1.025 and the ph at 8.3. but definately don't put fish in until you really have 0 ammonia and 0 nitrites. Also be sure you have a nice clean up crew working on the sand. I think this is all you can do for now.

 

[scsinet]

Originally Posted by lion_crazz
Well, the biggest problem with your tank and keeping fish is the ammonia level. Any ammonia present in the tank is dangerous. That alone will kill fish.

I'd concur. Your ammonia level is likely causing this. Ammonia burns gills causing death by asphyxiation. Corals aren't really suseptible to this, at least not at these levels. Your ammonia is not very high, which could explain why they live for a month. Regardless of that, ANY measurable level of ammonia in a captive system is unacceptable. You need to find out why this is happening. Causes:
Overfeeding
Uncured live rock
Death of animals in the system (crabs, corals, fish, etc) and non-prompt removal
Excessive feeding of invert foods (microvert, DTs, etc)
Insufficient biological filtration
Another possibility is that salinity.. 1.027 is higher than normal, but I've seen reef systems running on 1.026 so I doubt that would cause the deaths you describe. Besides, it would kill your inverts first.

 

[butrfly253]

What would be the best way to lower the ammonia in the tank? Should we add more snails and crabs? Thanks.

 

[scsinet]

It sounds like you are lacking a basic understanding of the nitrogen cycle. Knowing how it works and how it related to your system is something that every hobbiest should have firm grasp on. I don't mean to lecture so I won't. I recommend you get your hands on a copy of The Conciensious Marine Aquarist by Bob (Robert) Fenner. You'll find his book invaluable.
But to address your specific question, ammonia is broken down by your biological filtration. You haven't told us about your filtration system yet. You said that you have an Aqua Clear 70, but I believe that is a powerhead... maybe you have a chemical module attached to it with carbon pellets, but is that your only filter? Do you have a canister? Sump? Hang on Back (HOB)? Are you using a protein skimmer?
When waste is introduced into your tank by a dead fish, decaying food, fish urine and feces, etc, it rots. This generates ammonia, which is incredibly toxic and therefore extremely dangerous to your fish. It has the effects I stated above. The beneficial bacteria in your filtration system (a biological filter) breaks down ammonia into nitrites. These chemical compounds are less toxic but not safe for your fish. Finally, the bacteria breaks down nitrites into nitrates, which is removed by your weekly water changes.
Therefore, to address an ammonia problem, you need to stop adding fish and let your bacteria build up. You can jump start it by adding a product called Bio-Spira to your system. It won't hurt any of the animals you currently have. It's very expensive (a 55 gallon treatment is about 30 bucks or so) but it works. Then, you continue testing every day until your ammonia reads 0.0. Check your nitrites. They should also be 0.0. Check your nitrates, and do a series of water changes maybe 20% per day until they are under 5. Then, and ONLY THEN, add exactly one fish to the system. Use a clownfish or a damsel. Once you've had it for a month, add another fish, then another, etc. Keep checking that ammonia and if it ever rises above 0.0, stop adding fish until it goes back down.
Tell me, how did you cycle this tank when you started it up?

 

[scubadoo]

Originally Posted by Butrfly253
What would be the best way to lower the ammonia in the tank? Should we add more snails and crabs? Thanks.
Your test kit may be inaccurate. SOme ammonia kits may give off false readings.
I would eliminate that possibility first.