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From: JS

I was wondering... how does everyone acclimate their fish?

One way I have heard of is to float the bag in the aquarium (with the lights off) for ten minutes (with the bag open), then add a little bit of water every 10-15 minutes. After 35 - 45 minutes, gently release them into the aquarium.

I have also heard of another way... Put the new fish in a bucket (with the water that was in the bag) and use a length of airline tubing, pinched with a clothespin to slow the siphon. That way it drips into the bucket and slowly acclimates the fish to the pH and salinity. But what about the temp? The small amount of water in the bucket would cool off too quickly. Any ideas?

From: BC

Personally, I acclimate my new fish by the first method you mentioned. If using this way however, remember to NOT add the water from the bag, even though it is mixed with your own tank water. Dump that water out in the sink or someplace.

I personally believe that messing about acclimatising fish for more than a minute or two is more stressful than just tipping them in, I always just open the bag let it sink for a minute or two then tip `em in, never had any problems.

This idea of drip feeding water into a bucket is totally over the top, also don't panic if you tip the dealers water in your tank if you don't trust his fish and water to be disease free then you shouldn't be buying off them...

GS, glad to hear that you’ve not experienced any problems from this method…You may be way ahead of me but begging pardon, how do you know that this method of acclimatising has not had any adverse impact? Have you not had any mortality over the period you’ve been up and running? If you’ve not experienced problems, I believe it’s an exception (probably even among this group) and not the rule.

IMO I believe that encouragement to follow tried and true procedures that eliminate as much deleterious effects as possible is necessary with marines. There’s so much at stake which precludes the risk involved.

At best, a quarantine set-up should be used; at worse, some degree of acclimatising livestock should take place.

GS. Personally I disagree with you, I WILL NEVER pour the water from the dealer into my tank. That will introduce every nasty thing that you could imagine into your tank. The least you can do is to equalise the temperature of the water, then release the fish. I will never sacrifice the water quality in my tank just because of being inpatient. Personally I use the floating bag method.

Boy! What a question. There is a LOT of parameters to this question. For example, if you are introducing a fish into a F/O tank.... Is it bigger than the others, smaller, predator, non predator? Being introduced to a tank with or without predators? Is there copper in the tank? Is there copper in the water from the LFS? (Probably). If you are introducing the fish into a mixed reef... Is there copper in the LFS water? (Probably) Are there any fish of the same species in the tank now? Is that species or any of the fish in the tank aggressive? Will the fish eat any of the coral?

That being said...

When I am introducing a fish into my F/O tank, I float the bag (sealed) for about ten to fifteen minutes. It so happens that I use low dose copper in my F/O tank so adding the LFS water to my F/O tank is not a problem. To keep down aggression after releasing the fish, (Right after the float of 10 to 15 minutes), I OVERFEED the tank. Fish seldom fight when there is PLENTY of food. Before the feeding is done, I turn off the lights, and leave them off for the day. The next day, I OVERFEED and turn on the lights, then before the feeding is done, I turn off the lights again. I follow this procedure for 3 or 4 days. I have never had a problem with getting a new fish to join well.

My acclimation process consists of the following-

1) open bag
2) net fish out, put in tank
3) toss out transportation bag and water

Now, this isn't the best method for everyone. If your fish will be in the bag for less than a couple of hours, go right ahead and do the slow method. For those of us whose fish will be in the bag for several hours, we have all new problems to deal with. Any fish in such a small closed environment should, by all rights, die within a few hours from it's own production of ammonia. However, by it's own respiration, it produces CO2, which sort of acts to lower the toxic ammonia levels (I'm not going to go into the actual chemical process here, re: ammonium ions, blah blah). If you then add fresh tank water to the bag, you release that ammonia, which can poison your fish.

Trust me. Just net em out, and toss the water away. The temperature change, as long as it's not too drastic, shouldn't hurt them, either.

IMHO, a holistic approach is always the best, regardless of what we do/change/add to our tanks.

As JF mentioned, adding copper treated LFS water to a mixed or invert tank can be disastrous. This LFS water is also usually of a lower salinity than our tank water, the pH is probably different, and if it's from a "fish only" holding tank, the nitrate level is also probably sky-high. So, GH, it's not only a matter of water temperature, or of "trusting" the LFS. (By the way, all LFS's work on an expected mortality rate in their tanks - having some fish sick or infected is not a disaster for them, but it is for me. Therefore, I will never trust any LFS totally, even if I buy their fish).

As for the slow mixing of tank water (partial replacements or dripping), it's not so much to equalise temperature, but to reduce the shock (stress) of differing salinity and pH. Given that our fish are remarkably tolerant of changes, IMO it's still unnecessary, cruel, and unwise, to subject our fish and inverts to such drastic changes.

For the record, I place the fish or invert, with all the water in the bag, in a goldfish bowl. I then place the goldfish bowl in the sump, to equalise temperature while the water equalisation is taking place. I then drip water from the tank into the bowl, doubling the volume over ~ 45 minutes. As the bowl fills, I siphon off the excess water, and discard it. I keep this up for one to two hours, thus diluting the original water to ~ 15% - 20% of it's original volume. I then net the fish, or remove the invert by hand, and release it into the tank.

I tend to use a relatively short (10-15 minute) transition time myself, so I don't totally disagree with CK's technique. But since I have heard that dilution of travel water by adding tank water into an open bag would ease transition stress I wonder if you (or anyone) could expand on your observation/position regarding increasing ammonia toxicity with this method? Any links or references would be great, if available. Also, I understand-- and would like feedback on this--that inverts need more effort to stress buffer and fish need less?

BTW, I should add that I tend to use sources of livestock that only require 5-20 minutes of "travel time" before I get to my tank. For what it's worth, I generally ask for larger and double bagging with a good shot of O2--just 'cause I can and they will. :)

This is really turning into an interesting, and valuable, discussion.

I also believe in transporting my animals in lots of water. The LFS's usually try to convince me that only a small amount of water is sufficient, using the argument that one needs a larger volume of air "for the oxygen". Though oxygen is important, more water reduces temperature fluctuations and water pollution. IMHO it also "buffers" the animals from physical shock if the bag is bumped against something, or the car you're travelling in makes a sudden stop, etc....

Because I travel between 3 - 4 hours (sometimes it takes even longer) from the closest LFS to my home, I also pack the bags in a Styrofoam "cool-box". I use a little six-pack beer cool-box for a single bag, or a larger one if I have more bags. I also fill the space between the bags with about 3" of water. The LFS expects me to pay for this water, but I believe the added temperature- and "shock absorbing" buffer is worth it.

I agree with HL. I think I will go about it in that way. Just dumping them in the tank, IMHO, is way too stressful for the fish. Imagine temperature, salinity, and pH shock... all at the same time!

If you need to raise the oxygen levels in the fish bag, just add an airstone, or if you are worried about ammonia, add some Amquel or Prime (SeaChem) to neutralise it. The only thing is I need to create an "artificial sump". I'll just fill the 10-gallon tank 1/3 full of water, add a heater, and place the fish bowl (with the fish and the original water in it) in the "artificial sump". Let the water from my tank drip down into the bowl and take some water out of the bowl if it gets close to the top. After a while of this, I'll dump the fish in.