New member
I meet a severe RTN event in my tank, the RTN started a week ago and keep going worse. I lost one to two SPS each day. Almost tank crash now, even one clam looks dying. I had this kind of RTN event before but usually it would recover after few days, but this time it has no sign of recovering.
See what might be the cause of the RTN?

Before RTN:
. I had a water change with near exhausted DI unit. means TDS=1, it was TDS=0 for fresh DI unit.
.I adjusted CO2 level for Ca reactor. KH goes from 8.7 to 9.2.

During RTN:
.changed GAC and GFO media.
.removed a lot of sand for SSB.
.Added copper resin, but it didn't seem help.


Premium Member
I am sure he added a resin to remove copper, something like this:

Purple Haze

New member
Too many changes too quickly. In a situation like this it will be very difficult to determine the cause of fatality.

That is why it is wise to make one change at a time.

Less than a month ago I switched from a 14k bulb (Phx) to a 10k and lost color. Two days later I made the mistake of adding a GFO reactor and lost even more color. From now on it's one change at a time for a week or two, or more, and then another cautiously.

Best of luck.