Dwarf Crayfish, frost, outdoor tubs, an emergency vase

[Allan]

All right, exciting times here.

 

 

Spring was starting off really warm here in Illinois so I set up my tub outside and ordered some Brazos dwarf crayfish (cambarellus texanus).  They come and the temps drop back to 30 degrees at night.  Which I should have expected but I was excited.

Now, my guppies murder shrimp for fun so I can't put them in the same tank and my other tank has kuhli loaches and since the guppies murder shrimp I'm not even going to try with the loaches.  Enter the 1 gallon flower vase hotel.

I put some plants in the vase and noticed a smell, testing with coop strips the Nitrites are easily at 10.  How many back to back 50% water changes should I do? I did 2 yesterday and it came down a little, then another this morning.  My concern is changing too much too fast and putting them in shock before they get to their home, but also I don't want them poisoned.

[Comradovich]

Okay, remember that every 50% water change is going to drop your nitrites reading by half. You will get diminishing returns by doing more water changes, because half of half of half again is much less than half of the whole. You're going to have some nitrites. Since this is a newly started vase, I wouldn't expect it to hit 0 all at once. I would also caution you that the ACO test strip only goes up to 10, so you might be higher than this. If you take half of that away, you might still be closer to 10 than 5. The test strip is also calibrated for fish, some inverts may be much more nitrite tolerant than this.

I would do a 50% change now, wait an hour or so, then retest. If you're still near 10, see if the crays are showing any signs of distress and only really worry if they are. Crays are a bit tougher than fish are. They might not expire on you as fast as you're worrying they will. If they're actively trying to get to the surface and out of the vase, then it's time for another change. The pic makes it look more like they're just checking the plant for food. If you're going to aim for a goal, look for getting near 1, but doing so over several hours to several days. Slowly take things down so you don't shock them all at once. You need the 2nd stage of the nitrogen cycle to kick in and it's a bit slower going than the first. Have you got any seasoned tank water to do a water change with? This might be better than straight tap water, as it'll contain a few of the organisms you're trying to get started in the vase. While old tank water isn't the magic bullet we used to think it was, it isn't bad for starting a jar.

[Expectorating_Aubergine]

So long as the tub does not freeze solid, they should be fine. Texas can get pretty cold. They even get frost in some areas. I'd say keep them in the tub outside. Normally I'd say "put a pothos on it", but I know crayfish like to climb out and go on walkabout...

 

[Allan]

The first fill and first two 50% water changes were tank water. Then I switched to tap water for changes 3 and 4 since the nitrites were so high. 
 

They seem content in there, they go eat when I put food in and otherwise just hang out. 
 

I saw to keep them in 65-80° water so I’m not comfortable keeping them outside in 25°. 

Edited April 23 by Allan

[Allan]

@Comradovich

 

Thanks for the help.  Things are testing normal now. 

[Comradovich]

On 4/26/2023 at 11:34 AM, Allan said:

@Comradovich

 

Thanks for the help.  Things are testing normal now. 

Good to hear, hope the tub goes well for you. Yeah, I'm kind of the king of starting cultures in Kirkland Mixed Nuts jars from the ol' Costco. Lost count of the number of times I've looked at a test strip a day or so after I set something up and blurted out: "Oh, {BLEEEEEEEEEEEEEEPPP!!!}" Thing to remember about any new setup is that it's going to test high for something early on, stuff drops back down to normal levels if you just leave it alone long enough to cycle through. I know Father Fish isn't a big fan of the nitrogen cycle, but it's a useful construct to work from even if it isn't strictly true enough for some aquarists. Jars are like very finicky nano-tanks. Once you get them dialed in, they last and last, but they'll shock the life out of you at the start.