like 0.6-0.8 change. It is really strange why that specific store has a low survival rate of fish, so i assumed it was this reason. the other store's ph is the same as mine, around 7.8
You're OK here with a change that small. I would not make a habit of it, but provided your pH remains stable going forward the initial change is of little consequence. There are other issues at play here I'm sure. But the ammonia accumulating in a bag of fish from the store is far more dangerous, and the sooner the fish are out of that water the better.
If you want to test is the bag is breathable inflate it and heat seal it. If the bad Intisiallhy it will be a ridged baloon However if one time it looses pressure it will decrease and the the bag will no longer be ridged. IT that happens the bag is breathable. If that doesn't happen the bag is not breathable. Yet every time I order shrimp they packages takes at least 2 to 3 days to get delivered The bags were always iridged. This tells me that there was minimal amount of breathing occurring. Even if they claim to use breathing bags there is no indications of pressure loss in the bad.
The reality is that most thin plastic will allow gas to pass through them without holes. But at an extremely slow rate. So technically all plastic bags are breathable. But in reality they don't breath enough to prevent CO2 build up or ammonia build up in the bag. The sudden change from CO2 rich water with some ammonia to water with low CO2 and low ammonia can be stressful to fish and shrimp.So you should always allow time for the animals to adjust the new water . That either means putting the new shrimp in a bowl and then gradually adding in water from the tank by dripping it in or by cutting a small slit in the bag to allow tank water to gradually seep into the bag. after a hour or two enlarge the cut so that the shrimp can gradually work their way out of the bag.
The only plastic that is truelly breathable is with microscopic holes is Expanded PTFE (Gortex) And Gortex is translucent white not clear.
