Thanks everyone for your answers.. and the lecture 
Regularly the ph in the tank was 6.5.
And i will try that water sample sitting out of the tank for 3 days and see.
Another question for you guys..
Soon i plan to do some work on the tank, change the substrate, let it cycle fully again and only then i will start adding back those fish. Since these fish are used to such low pH and if i decide for the time being to add them to my other tank which has a pH of 6.8, should i increase the acclimation period or how should i go about getting them to the other tank safely and being there for say a week?
Regularly the ph in the tank was 6.5.
And i will try that water sample sitting out of the tank for 3 days and see.
Another question for you guys..
Soon i plan to do some work on the tank, change the substrate, let it cycle fully again and only then i will start adding back those fish. Since these fish are used to such low pH and if i decide for the time being to add them to my other tank which has a pH of 6.8, should i increase the acclimation period or how should i go about getting them to the other tank safely and being there for say a week?
