i would love to stop feeding for a few days but i gott a really skiny axolotl who im trying to buff up and when i say high i mean the second highest level on the chart!!!!!!!!!
I would suggest moving the axolotls out of the tank and into a plastic tubs/buckets, until you can get to the root of your problems with these skyrocketing nitrite levels in the tank.
In your other thread, you mention that one of your axolotls is shriveling in the tail region. This is a likely result of the nitrite spiking to deadly levels.
Every time you throw food into the tank for the axolotls, you are undoing the work of the partial water change which was to bring those toxic levels down. Removing the axolotls (and therefore the food which is fouling the water) from the water for a time will help solve that problem. For the sake of your axolotls health, please get them out of the that toxic tank until you've got it under control.
While living in tubs, the axolotls will need their water changed out once a day with fresh de-chlorinated water. You need to keep them clean, cool, and safe. Each time you change their water out, you can throw the 'poopy water' into the aquarium to feed the bacteria and keep your tank cycling.
Keeping them in separate tubs/buckets will also allow you to monitor their food intake and outtake, prevent food from being stolen from the skinny axolotl, and remove left over food promptly after feeding - all this is particularly important for the axolotl that is 'really skinny'. The clean water and stress free environment will also help the axolotl's withered tail heal.
He also needs nutrition to help him heal and get well. Earthworms, blackworms, bloodworm, and pellets are the best nutritional diet. Beef should only ever be a treat, never a staple food as it contains no nutrition for axolotls. It's also hard for the axolotls to digest, and can wreak havoc with water quality if left over bits are not removed from the tank quickly enough.
As the others have advised, still monitor and record the tank Ammonia, Nitrite, Nitrate, pH levels in the tank, even while the axolotls are not in there. This will give you an idea of how the tank cycle is going.
Have you checked the filter? What type of filter do you have? There may be food/gunk that has got clogged up in the works. If the filter has sponges, take them out and give them a good shake and squeeze in a bucket of water from the tank. DO NOT USE TAP WATER to clean the sponges, you'll kill the good bacteria if you do this.
How deep is the sand?
To give us a clear idea on what's going on, could you please provide photos of both your axolotls and tank setup.