School of Blue/Green Chromis dying off ?!?!

[eekball]

I recently cycled my 75 gal SW tank with damsels. Once the tank was completely cycled and the water conditions were perfect, we removed the damsels and added a school of 8 blue/green chromis'.

In the first 2 days we had lost 3 of them. The LFS replaced them for us so we had 8 again. Over the next week we started losing them one by one. The water conditions are still perfect and I don't understand why they are all dying. We are down to 3, as another one lay breathing heavy under some coral this morning.

Any ideas as to what could be killing them off?

 

[quarryshark]

Hard to tell. What are your water parameter? Mainly ammonia, nitrate, water temp and PH. Were they eating? Did you qt the chromis?
Need a little more info.

 

[austinsdad]

one lay breathing heavy

Could be a sign of high ammonia. I know you said the water was perfect, but either the ammonia readings were suspect or they are all sick. My LFS recently got a shipment of chromis and all died within 1 week, starting the day they arrived at the store. Got a replacement shipment and all are just fine.

I'm concerned that if no QT was used for them, there may be more problems in the main tank.

 

[Phyl]

How are you acclimating them? How long is the process? Have you checked the water parms of the bagged water just before transfer? Make sure that your PH & SG are as close as possible before you move the fish, even if it takes 3 hrs to move the fish. Some people have this die-off problem with Chromis. I can't help but wonder if it isn't the source of your fish that's the problem. I only added 3 to my tank (120) but I didn't lose a one of them.

What is your PH? SG? How many GPH are moving through your system? Where are your pumps and what is your head height? They sound like they're either severely stressed (is there rock in the tank?) or oxygen deprived. Are the wild caught or tank bred?

 

[eekball]

WOW! We acclimated them by floating the bag for 20 minutes or so. Then netted them. We did not add the water from the bag to the tank. Should we?

As far as the other questions, I will have to go home and check to see what all this is. Will get back on here when I have specifics. Please check back as I will post this info when I have it and maybe figure out what has happened.
Thanks!

 

[Phyl]

Proper acclimation for the fish would be to slowly add water from the main into the bag until you've doubled the volume of water in the bag. Then dump half of that water out (for disposal, not into your tank). Keep adding water. When you've doubled the volume of water again check the parameters and add the fish if the parameters match (SG, temp and PH) match. If not, repeat.

There are two ways to add water. One is to add a shot glas of water into the bag every 5 minutes. The better way is a slow drip acclimation (there's sure to be an article on this, but I don't have an URL for you. Check the articles section for them).

When you're ready to add them to the tank net them and put them in (don't add your bag water to your main). Try this with your next batch. In a 75g tank though 8 chromis would grow to be 24 inches of fish. Your shooting for 1" of fish for every 5g of tank which would put you at a max of 15" of fish for your tank (you can go a little over but you don't want to stray too far). You may only want three of these in your tank when all is said and done anyway.

What kind of pump(s) are you using on your system?

 

[austinsdad]

WOW! We acclimated them by floating the bag for 20 minutes or so. Then netted them. We did not add the water from the bag to the tank. Should we?

That could've been the problem. You only acclimated for temperature, not for the likely change in PH and salinity. There may be more critical levels, but I think those 2 are the biggest. If there is a large difference in those between your tank and the LFS, the chromis could have been adversly affected by the sudden change when you netted them after 20 minutes and put them in totally different water.

 

[quarryshark]

I agree, sounds like the acclimation proccess was the problem.
Also may want to consider setting up a 10 gallon qt tank for future animals.

 

[lando]

really sounds like an acclimation issue. However, just to be sure, can you post your current water parameters? Ammonia, nitrite, nitrate, temp, Ph, SG. YOu may also want to verify your readings with the LFS.

 

[Thumper]

Could be an acclimation process problem but if it's a newly cycled tank could it be that the tank just isnt ready for the bio load of that many fish this soon. I'm not saying it is but I would think that would be a shock to the system right there.
Sooner or later it's going to come back and bite you for not qt the fish as well, this comes from experience.

 

[eekball]

Our parameters are:
pH is 8.4 (recently it's been as high as 8.5 and as low as 8.2)
Alkalinity is normal
Nitrate just went from 0 to 20 the other day
Nitrite 0
Ammonia 0
Salt 1.021-1.022

Do these sound normal?

 

[austinsdad]

Did the nitrate spike @ 20 coincide with adding the 8 chromis? Ammonia stayed at zero within 2 days after adding them and feeding?

Just trying to narrow down on problems you're having.

 

[eekball]

We added the chromis on Tuesday the 25th and the other fish on Sunday, the 30th. The nitrates spiked on 2/2.

I think we have ich in the tank now though. The angel & tang are covered in white spots. I just started another topic (see thread titled "Fish have white spots, is this ich?")

The 3 remaining chromis look fine though.

 

[austinsdad]

Sounds about right IMO for nitrate increases due to heavy fish load in a newer tank. Didn't realize there were more than the 8 chromis. What other fish on the 30th?

I believe Lando said it earlier, the bioload may have been too heavy, too quickly.

8 fish on one day, and more 5 days later. That will stress fish and likely cause an outbreak like you're experiencing now.

I did that too when beginning. Hard not to want fish. I added too fast, nitrates went up, and I had a velvet outbreak. 9 fish died inside of two weeks.

 

[Salttanker]

About how long was the cycle? Many times, people are excited about adding fish to their tanks too soon. I have always used a good rule of thumb: Let it cycle for 6 weeks, then test it. I know some tanks may cycle faster, but in the beginning stages of a SW tank, conditions are more fragile than they appear.
Also, you may want to consider only adding 1 - 2 fish at a time. This will help keep the strain off the bio load. In a more mature tank, you can generally add a few more than usual because the tank is ready for it.
If you have ick, you can try to treat it. Although it is better to treat in a QT rather than the main. If it is ick and you do lose them, you will need to leave your tank fallow (fishless) for 4-6 weeks so it will completely die off. HTH

Mike