Drip Acclimation

[cvsailer]

I was told by my LFS store (who I believe is very credible) that you should always drip acclimate new fish into QT. I've read on RC that this method could be dangerous or even deadly, why? Thx!

[blanden.adam]

It really depends on the situation:

When you buy a fish from an online retailer (rather than at your LFS) and they ship it to you, the fish has been in transit in a closed container without biological filtration for a substantial period of time. In this situation, 2 things happen. 1) Ammonia from fish waste builds up, and 2) CO2 from the fish breathing and inability to exchange gases with the surrounding air builds up. However, the increased CO2 drops the pH, protonating the ammonia molecules to the less toxic ammonium ions. So, when you get the fish and start drip acclimating it, the water can equilibrate with the air and your quarantine water raises the pH of the water the fish came in, resulting in deprotonating of ammonium to form the now more toxic ammonia again.

So, you have to weigh the relative risk of giving your fish osmotic shock by not drip acclimating him versus the toxicity of the ammonia in the bag. When you buy fish from your LFS, ammonia is not really an issue because you just drive the fish home (no time for it to accumulate), so always drip acclimate them. When you order online, that's a different story. Fish generally tolerate drops in salinity rather well (not at ALL for rapid increases in salinity), so if you maintain your QT at 1.021 or something like that, the drip acclimation can be avoided (provided the water the fish came from was greater than 1.021) and the salinity raised slowly over the next few weeks to match your DT -- although certainly not ideal, it can be the best method in a bad situation.

It is for this reason that I do not drip acclimate corals -- They don't seem to get stressed by osmotic shock like fish do, and I'm much more worried about ammonia toxicity and temperature issues. That's my take on it anyway.

[whiteshark]

^^ That is very good info.

I drip acclimate my fish with no problems. The only issue to be careful of is water temperature. If the room is very cool the water can get very cool in the acclimation vessel. Otherwise, I've had no real issues with it.

[Sk8r]

Read the sticky on acclimation: that will explain further.
Basically fish excrete and breathe in the bag. This produces ammonium, which is harmless if not excessive.
When you open the bag c02 escapes.
This changes the bag ph. This causes ammonium to become ammonia, which is lethal in small doses. This transition takes about 30 minutes. If your 'drip' lasts longer than 30 minutes, you can kill your fish, if the level of ammonium in the bag was higher than a certain level. This is particularly true in shipped fish.
The whole object of drip acclimation is to adjust ph (which has shifted violently anyway) and salinity.
Don't do this.
Adjust your quarantine tank's salinity to match the lfs you use, then don't acclimate at all, beyond just floating the bag 15 minutes to adjust the temperature. {The fish is safe in there until you open the bag.]
Open the bag, test both salinities to be sure, and if within .002, extract the fish with your hand if not poisonous [gentler than net] and slip him into the qt tank.
Leave the qt light off except for observations, no sand, no rock, and change the filter floss every time it stains.

My take on drip acclimation is that it's probably killed more fish from ammonia than it's saved from osmotic shock. Fish swim between salinities in the ocean: they cope with small changes. If you prepare that qt tank properly, and adjust it toward your tank salinity slowly over weeks in qt, you're doing better for your fish than any drip acclimation, particularly exceedingly slow drip acclimations. I don't know how many sad posts I've read that start with "I don't know what happened. I acclimated him for over an hour..." and I so hate telling the owner what went wrong.

[MrClam]

When you open the bag c02 escapes.
This changes the bag ph. This causes ammonium to become ammonia, which is lethal in small doses. This transition takes about 30 minutes. If your 'drip' lasts longer than 30 minutes, you can kill your fish, if the level of ammonium in the bag was higher than a certain level. This is particularly true in shipped fish.


This is great information. I am curious if anyone knows if this process is the same for freshwater? Fish shipped will still release ammonia, but I am unsure of the change in pH. My inclination is that freshwater is going to have less of a pH buffer and will likely shift more due to CO2 buildup so drip acclimation would be even more harmful.

Another related question, sk8r why do you say it takes 30minutes? Is it a gradual change from ammonium to ammonia over 30 minutes? In which case a short drip of say 5-10min may be beneficial?

[Sk8r]

THere is where you will have to ask Disk One in the Chemistry forum. He's much more the chemist than I am, for sure! I do know that 30 minutes you are still safe, but beyond that, not, and that might (or not) have to do with how much ammonium was present in the first place, and when the water will reach lethal levels on conversion to ammonia. .

The sneaky, nasty thing about ammonia poison is that the fish often looks fine---and dies of organ failure about 3 days later, which is probably kidneys failing and letting toxins build up in the bloodstream.

[cap032]

Sk8r, just curious, but what if you added Prime to the bag the fish is in before you started the drip? Would the Prime remove the ammonia and make the drip acclimation safer?

[Sk8r]

I'm not the chemist. I don't know whether Prime acts because it converts the ammonia to ammonium, or whether it somehow changes it to something else... but put it into a bag that's already got ammonium and I wonder if it will act as the ammonium turns, or just what happens. That's another Disk One question.

[cap032]

I'm not the chemist. I don't know whether Prime acts because it converts the ammonia to ammonium, or whether it somehow changes it to something else... but put it into a bag that's already got ammonium and I wonder if it will act as the ammonium turns, or just what happens. That's another Disk One question.

Thats what I was wondering, would it act as the ammonium turns. If so that would great news.

[Susan Lohrer]

For what it's worth, I tested the water my starfish arrived in today (overnight shipping, and the bag had been open for twenty minutes), and the ammonia read at 1 ppm. So I dumped almost all of his water and started trickling in the tank water fast. I really hope he makes it.