How Do You Acclimatisation New Fish To The Tank?

[ey2006]

In a general, freshwater community tank, what is the best way to acclimatisation new fish?

The LFS usually say, float the bag for 10-15 minutes, add some tank water, wait for another 10 minutes before tipping everything in, including the water in the bag.

Personally, I never put any of the water in the tank, who knows what bacteria may be in the LFS tank water? Not worth risking for sure.

I guess my question extends more to the duration of the whole process. The process I explained above probably takes no more than 30 minutes. But I have read that the proper and appropriate way of acclimatising fish is a process which takes at least an hour, and sometimes even 2 hours....whereby you have to make sure the temperature is slowly matched, and even trying to match the water parameters - ammonia/nitrIte 0, nitrAte and pH

How do you acclimatise new fish?

 

[Qays]

30 mins. after 15 mins, put some tank water in, do this a few times until its about equal. Net the fish into the tank.

 

[carrera]

i have read that it takes days for a fish to get used to differences in ph/hardness/anything else, not minutes or hours, and that anything other than a 30min float to equalise temperatures is a pointless exercise.

 

[Sheridanp]

I might sound like a monster, but I just add the fish. I take the bag, put a net over a bucket and pour the bag into the net so the fish are there and not the water.

 

[carrera]

I might sound like a monster, but I just add the fish. I take the bag, put a net over a bucket and pour the bag into the net so the fish are there and not the water.

i do that after a 30min float

 

[Qays]

Why wouldnt equalising the temprature be pointless?

 

[carrera]

Why wouldnt equalising the temprature be pointless?

well i guess that is the change that is the most 'sudden', being dropped from cool water into warm water.

 

[TwoTankAmin25]

Actually it is Ph differences more than temp differences that may effect the fish. I have acclimated some fish overnight and I have also dumped some into the tank ASAP. The latter happens if you have fish shipped in and the bag water is nasty when they arrive. Ammonia laden bag water is more harmful to a fish than most parameter changes.

 

[@ombomb]

I now use the drip method, last fish was acclimatised for just over 1.5 hours before being added to the tank.

 

[Saedcantas]

Here's my introduction schedule

-Turn off tank lights!
-Remove the bag with the fish in from all the other bags they were in, cut the knot off and roll down the top, remove one cupful of shipping water and pour away float the bag in the top of my aquarium.
-Test the water the fish came in to ascertain just how much of a change this is going to be.
-Add one cupful of my own water to the bag.
-Wait five minutes, take another cupful out of the bag and pour away then add another cupful of tank water to the bag.
-Repeat the above a total of about 3 times for hardy/not particularly sensitive fish/ fish from water very similar to my own tank water or repeated more like 5-6 times for easily stressed fish or fish from very different parameters to my own.

After that time I remove the bag from the top of the tank place it in a bucket I have that holds the bag upright, gently net the fish out and place them in the tank once you're done just pour away the water in the bag and leave the lights off for about another hour.

I've always done things this way, some might say not enough care taken and others might say overkill that does nothing anyway, it's a matter of what works for you and this always has for me, I have never had a new fish die or bring in disease and cause an outbreak in my tanks

 

[Bignose]

i have read that it takes days for a fish to get used to differences in ph/hardness/anything else, not minutes or hours, and that anything other than a 30min float to equalise temperatures is a pointless exercise.

You may have read that, but the science does not support this point of view. The facts are that pH changes during the day in lakes in ponds. Sometimes, by more than 2.0 whole pH units. pH is also temperature sensitive, so as the sun heats up a lake, the pH also changes. The fish that live in those lakes cannot take 'days' to get used to it, otherwise they would be constantly living in stress.

What the scientific papers do talk about is that a difference in hardness is the most difficult to overcome, but even then it does get dealt with in a matter of a few hours, not days.

Here's something I posted a few months back: ( http/www.fishforums.net/index.php?showtopic=123152&hl= ) According to Evans, Piermarini, and Choe "The Multifunctional Fish Gill: Dominant Site of Gas Exchange, Osmoregulation, Acid-Base Regulation, and Excretion of Nitrogenous Waste" Physiology Review 2005, the return of blood towards the control pH is primarily due to adjustments of blood bicarbonate concentrations via exchange of acid-base equivalents at the gills. Over 90
% of the action occurs at the gills.

Basically, what is boils down to is that the fish exchanges CO2, Na+, and Cl- at the gills until the pH balance between the water and their internals is just the way they want it. Another quote from the above article: "Although variable with the type and extent of the acid-base disturbance, compensatory transport is usually activated within 20-30 min of the disturbance and can reach net-acid or net-base excretion rates of 1,000 micromol per kg per hour."

If I just let the flux rate be 100 micromol per kg per hour, I think that that means that the fish can change its internal pH around 4 units per hour per kg of the fish or faster down to a pH of 4.0 (after that the time starts increasing exponentially, i.e. 10 hours to get down to 3.0) I actually don't know what the internal pH of a fish is... anyone?. So, smaller fish (smaller kg) can change their pH faster -- makes sense, smaller circulatory system, easy to change concentrations in a smaller volume.

What is really interesting is that the acid-base exchange rate is also dependent upon the salt (Na+ and Cl-) solution, so GH and KH play a much larger role than may be usually suspected. This thread http/www.fishforums.net/index.php?showtopic=123070 started just the other day linked to a site whose author deduced this relationship from experience.

So, it appears if the salts in the water are favorable, most aquarium fish can adapt to a change in pH pretty quickly -- in a matter of minutes really. But, if the changes in salt and total dissolved solids are big, the fish may not be able to use its ability to adjust its pH and that causes shock. In a funny analogy, a change in TDS is to fish's ability to change its pH like kryptonite is to Superman's super strength.

 

[SiriusStarr]

At the LFS I work at, we tell customers to float the bag for ten minutes, open it up, add a cup of water, float another ten, and another cup, float another ten, then scoop them out with a net and to NEVER added the bag water to the tank (since there's probably waste and therefoe ammonia in it now)

For Marine we tell them to do it for longer (15-20 minutes between cupfuls) and lights off, as well as for more sensitive fish.

 

[carrera]

i have read that it takes days for a fish to get used to differences in ph/hardness/anything else, not minutes or hours, and that anything other than a 30min float to equalise temperatures is a pointless exercise.

You may have read that, but the science does not support this point of view. The facts are that pH changes during the day in lakes in ponds. Sometimes, by more than 2.0 whole pH units. pH is also temperature sensitive, so as the sun heats up a lake, the pH also changes. The fish that live in those lakes cannot take 'days' to get used to it, otherwise they would be constantly living in stress.

What the scientific papers do talk about is that a difference in hardness is the most difficult to overcome, but even then it does get dealt with in a matter of a few hours, not days.

you may be right, but surely wild fish and captive fish are completely different. ie, a fish living in water that constantly changes pH would have adapted to such conditions, whereas a fish which has lived its entire life so far in the same water conditions suddenly introduced to different parameters (acclimatised 'a cup at a time' or not), would not be able to adapt to the change so quickly.

i used to use the 'cup at a time' method, but when i did read it was pointless, it made sense. 30 minutes or so of just dumping tank water on top of a fish a cup at a time to reduce introduction stress?

anyhow, right or wrong, since then ive only ever equalised temperature and, maybe ive been lucky, but ive never lost a fish to it and all my fish have been happy, active and feeding within the day, just like they were when i used the cup-at-a-time method.

 

[qwikimpss]

I gotta say that, personally, the drip acclimation method has to be the best. Since I started using this method I have yet to lose a fish because of shipping stress.

It seems to me that, even if a fish species has been bred in captivity for let's say 20 years, and that is the same general population that tracks all the way back to the beginning so that would be, for sake of argument, 40 generations of fish.

So, in the wild with fluctuating water parameters the fish would have evolved to cope with such changes over thousands upon thousands of generations. To evolve to requiring just a single PH range would take a lot more than 40 generations of fish as evolution takes a lot more time than that (if you believe in that sort of thing).

The fish may be very used to a certian, narrow PH range, but shouldn't be adapted to that one specific range (unless it is in the wild of course).

 

[Teelie]

I just chuck them in now. Haven't had any losses from it yet. Saltwater on the otherhand, when I do those, it'll be the drip method.