Fridge water change query

I am going on holidays for a week next week and during that time I will be putting my axolotl in the fridge and having a friend come over twice to do water changes. I know it is recommended to do 100% daily water changes when keeping your axolotl in a small container in the fridge, but I am wondering if it is going to be ok to do it every few days for a week?

Going to put him in the fridge two days beforehand so that if he regurgitates or poos that will be changed quickly. Hopefully it will be all out of his system before my holiday and then the waste he has will be smaller. Will be keeping him in 1.5L of water. Anyway if this is going to be a big problem I will try to organise more water changes.

The potential problem is ammonia build up. Can you measure the ammonia and pH of the water after the axolotl has been in it for 24 Hours and see how high it is? You can then calculate what the level will reach after two, three or four days. The level of toxic ammonia is about half the level at 7 Celsius than at 17 Celsius. Do not let the axolotl warm up in unchanged water at the end of its stay. Change the water before warming. The bigger the container the less the problem. My guess is a healthy axolotl in 1.5L will be OK for 3 days unless your water is very alkaline.

I have checked the levels of ammonia in the past and it was 0 after one day in the fridge. That was at about 8C. Was not sure if ammonia increases exponentially or steadily though... Water will be about 7 PH so it sounds like things will be ok for a few days with no water changes. Also, I always do a water change before bringing out my axolotl from the fridge to be warmed up

I am curious though, I thought the ammonia tripled as the container warms up from fridge to room temperature? I have had a few different comments in this area so wondering if anyone has any source for how ammonia reacts to temperature changes? Google has been unhelpful with the terms I have been trying.

So anyway, I think I will just instruct my friend to do the two water changes over the six days and will just tell her what to watch out for.

Thanks!

Saspotato - 1.5 litres is not very much water and toxins are more likely to build up in a smaller container if it is this small over a period of 3 days, as opposed to a larger container. Ammonia doesn't necessarily start to build up within the first 24 hours, but it is still best to stick to the daily complete waterchanges on a small container.

I have seen the results of an axolotl being left in the fridge after two and a half days in a 2litre container filled with just over 1 litre of water without being changed. The water smelled, the axie looked sicker than when it went in (it had only been placed in the fridge for bum floating), had grey patches on it's skin and looked dead. Thankfully it wasn't but I brought it home and looked after it till the owner returned (he'd shot up North to his Dad's tangi/funeral and had forgotten about his axolotl in the fridge = called me two days later).

You might be able to get away with the 3 days/twice a week waterchange if you use a much larger container - say the size of a vegetable fridge container and just don't feed it for a couple of days beforehand nor during your time away, but I'd still be a bit wary about it.

If you intend keeping it in that size container is your friend able to take your axolotl to her house and do the daily waterchanges till you return?

Ok fair enough. The water will actually be changed every two days, not three now. I will grab a bigger tuppaware container from the shop and put 3-4L in. I was concerned that even though ammonia is 0 at 24hours, that it can increase a fair bit after that.

My friend's house heats up as hot as mine and her fridge isn't going to be warm enough so that is why I am keeping him at mine. Her place isn't really an option though unless my axolotl starts to become ill. We did consider using one of her tanks for my axie, but this is not ideal as she would have to rehouse all her guppies and catfish. And again, there is still temperature problems. I think if my axolotl started becoming stressed I might ask for her to move him to hers and ask her to monitor the temperature and use ice-bottles and such.

I won't have fed my axolotl for three days before I go away, in preparation for the trip. So hopefully that will negate some of the effects.

Edit: Ok I have a solution after some thinking! I have just cleared out all my bottom fridge space so I can fit two 10L buckets in there. Anyway, I am going to fill them both up and my friend can just swap him from one to the other (replacing the water in the old one for the following water change). So that way he will be in 10L of water for two days. Hopefully this will be a lot better than my other ideas.

NH3 versus NH4+

My understanding is that test kits that test for 'ammonia' are actually measuring the combined concentration of NH3 (ammonia) and NH4+ (ammonium). The level of ionisation (how much NH4+ exists compared to NH3) depends on the pH of the water and also the temperature. It is the NH3 that is much more toxic to the axolotl than the NH4+. (Just like 'ammonia' is more toxic than 'nitrite' which is more toxic than 'nitrate'.)

I found an example table at http://fins.actwin.com/aquatic-plants/month.9507/msg00139.html but I think this has a mistake in it (68F/pH8 should be 3.82).

Looking at the table you can see that at 20C pH7 the percentage of very harmful NH3 to harmful NH4+ is 0.4%. If the water is warmed to 30C then the percentage increases to 0.8%. Whilst I couldn't readily find data at fridge temperatures, you get the idea of what's happening.

Interestingly, you can see from the table that pH level has much more to do with the toxicity of the 'ammonia' than temperature - at 20C going from pH7.5 to pH8.5 increases the proportion of NH3 to NH4+ by 10 times.

In short (to answer your question) I think it increases exponentially (x3 for each .5 pH increase and x2 for each 10C increases). Hope this helps.

To answer your original question about keeping your axolotl in the fridge - I think the bigger the better container and not feeding for a few days before hand are probably good recommendations, but don't stress about it on holiday. Your friend sounds like she'll take good care of him.

This proposed care regime sounds good with plenty of margin. tyl3r's summary is correct. If your water really does test as pH7.0 you can go up to a level of about 14mg/L total ammonia at fridge temperatures, at pH 7.8 only 2mg/L will produce about the limit to keep un-ionised (toxic) NH3 below 0.05mg/L which is the level I work to (has anyone seen a reference specific to axolotls?). I've seen a table somewhere which covered all temperatures and pH changes of NH3/NH4+ I'll try and re-locate it. Meanwhile have a nice holiday.

Thanks tyl3r for that info and also to everyone else for the feedback. Anyway, Maxolotl seems content in the fridge in his bucket set up so hopefully will be in one piece when I get back!

Why doesnt she just leave it in the tank?

It would be easier for the axie too, with the room and all.

I'm sure the person who is looking after it could come and feed it and what not.

That what we do when we go away.

And they have been fine.

Sarah doesn't want to leave her axie in the tank due to temperature issues (over 20c). Even a few days in temperatures over 22C can stress an axolotl which can lead to fungus and sickness. Once an axolotl gets stressed during the summertime and develops fungus, it just lowers its immune system and makes it more susceptible to other illnesses. If it was cooler weather (under 20c) then it wouldn't be a problem. Her carer can only come in certain times a week as well by the sounds of things and is unable to keep it in her own fridge nor is the carer able to house it temporarily in a tank at her place.

Thats ok, I was just wondering.

I've never used the fridge for my axies yet.

I've only had axies for 9 months, still new to this all

Yea kapo is right. I couldn't guarantee that the temperature would stay below 20C whilst I was away so the tank was not an option. Anyway, I am back now (had to come back early in the end anyway for scuba diving - nice weather on the weekend! ) and Maxolotl is doing well

Thanks again for your advice people