HI There
just a small note i added 205 to my tank in December i did have one temporary problem a pH drop so just for a while watch for this it should settle down after a few weeks and return to normal.
I just added some bread soda which brought it back up to acceptable levels till things returned to normal. i used the the trail and error method to find the correct amount a measured amount of water in a jug and added the soda till i got the right reading then worked out the amount i need for the tank. which i added slowly over a few hours to avoid pH shock.
PH shock

is one of the biggest killers of new stock in some people opinion