Lots of foam after water change?

[Frank H]

I have this tunze 9012 dc skimmer on my 5 week old tank that just finished cycle. I've done two water changes and both times the skimmer goes nuts, filling the cup very fast (3 full cups in less than an hour). I have even turned the tunze dc controller all the way down and it's still foaming like crazy.
I'm new to saltwater so not sure if that's normal for a skimmer or what's going on. Any info would be great!

Its bedtime soon, been almost 4 hours since water change, just dumped another full cup, and its filling up fast again. Can I unplug it over night and plug it back in in the morning? I dont want it splashing all over the place when it fills back up and overflows.

Its literally 5 minutes since I dumped the cup and its already a third full. Gonna need to top this tank off with a couple gallons of saltwater, which will probably start this all over again. I dont know what to do.

 

[Frank H]

 

[Frank H]

10% water change from RODI mixed with Red Sea Coral Pro salt.

 

[rvitko]

I suspect a different salt would solve this, Red Sea salts are made at least partially from evaporated sea water, they are generally discussed on forums as containing some dried organic matter (plankton, etc), this is not necessarily a bad thing but this is likely the cause. You could stop the skimmer, turn it down or try another brand of salt. I use hW Reefer and I don't have this issue unless the water level is changed and I change 15% every 2 weeks.

 

[Frank H]

Gotcha. Thank for the info Roger. I raised the skimmer a tad and its behaving normal now. Ill keep an eye on it next water change and consider changing salts if it keeps happening.

 

[rvitko]

I had one other thought, if your source water is RO with only the salt added, it has to be the salt mix causing it, but if you use a dechlorinator or stress coat that will definitely cause a strong foaming reaction from the skimmer. In general I would not expect an instant reaction from plankton, but some salts do add colloids and other organics that can cause a strong and instant reaction from the skimmer.