Acclimation

Proper acclimation is often not what many people are told it is, or assume it is – which is that they may simply float a bag in water and then release the animal. That form of acclimation is in fact just that, one form. It is a temperature acclimation and would only work in the case of 2 identical or very similar water sources. Most fish, especially most smaller community fish, and most invertebrates will require a full acclimation to adapt well and withstand the stress of changing environments and/or shipping. A proper acclimation involves adding small amounts of the source water to the bag in which the animal is in. This will slowly change the water chemistry in the bag, to that of the new system, or destination for the new animal. Most critical are changes in pH and salinity, however, even changes in NO3 can be stressful if they are extreme.

After the initial acclimation, there is also a process of further acclimating for an animal.  This is usually less critical but also must be thought out.  Adding a fish to a sump system, or sheltered area of a tank is key in minimizing stress caused by other inhabitants.  Sometimes it is best to add more than one fish at a time to reduce the instance it being singled out.  Adding fish after existing fish have been fed, adding fish at night or with the lights off, and changing the existing décor are also useful methods of minimizing stress to new fish.  Plants are often kept immersed, out partially out of the water since there is much more CO2 in the atmosphere and it is much more economical to administer it in this way.  These means that when you purchase plants, they will often times need to acclimate in the method of how they gather CO2.  Our plants are kept emmersed and usually have already “reprogrammed their pathways” to obtain CO2 from the water column.  Most photosynthetic organism, in particular corals, will also need to be photo-acclimated.  This is most true for Ricordea Yuma and most Chalice corals (oxypora, echinopora, echinophyllia).  Photo-acclimation entails placement of a coral in a lower light setting than from which it came, since the coral may already be stressed.  Failing to do so can not only cause a coral to release it’s zooxanthellae or “bleach out”, but also to die. 

Advanced acclimation (usually only necessary when numerous fish are shipped in one bag, for extra large fish, and sometimes marine fish) involves lowering the pH in the source water to that of the water in the bag, which may have dropped dramatically as the O2 in the bag was depleted. It also requires avoidance of the gas exchange that will occur upon opening a bag: example – 200 tetras are shipped in a standard 12x20 bag. After 24 hours in the bag the majority of O2 has been depleted and the pH in the water has dropped to the low 6’s.  Upon opening the bag the CO2 in the water quickly dissipates and the pH rises swiftly, thus stressing the fish further.  Solution – open the bag slightly at a submerged point so that no gas exchange occurs, and only small amounts of water are exchanged with the new water via diffusion.