Thank you guys for your suggestions. Pentaxuser, dektol will be ok in slot for about one day. Ilford multigrade will be ok for about 1 week. I print twice, maybe three times a month, so if the developer is more than two weeks in the slot, it is no good. It looks that for my infrequent print sessions, I will go back to trays and will use dektol, and discard after one time use. With ilford multigrade at 1+9 dilution, I should be ok to store the developer back to amber glass for the future print sessions?
Also I will try Ansco 130 or Liquidol which I was told it has good keeping property.