Does stopping carbon dosing...

[Craigdillman]

This is totally normal ,

the carbon dosing that you slowly built up over the period of time built up the extra bacteria that was handling your nitrates semi- effectively as they were still 10 which is high, now all of a sudden you stop dosing the carbon and all that "extra" bacteria goes away. Since you changed nothing else no extra WC or less feedings or more skimming, Your tank goes back to high Nitrates cause the carbon dosing was the "fix" for it or "bandaid" if u will.. Nothing wrong with that lots of tanks (mine included) only are successful cause of healthy carbon doing on a daily basis ( Zeo tanks, Bio pellet, Vodka...) these things need to be tampered on and off slowly or this happens . Im guessing that your nitrates have always been a bit on the high side and when u started carbon dosing it dropped it down to 10-20 level but when u stopped it rebounded ..

2 things you can do to fix it

1) start carbon dosing again , vinegar/vodka is the easiest then to bio pellets then full zoo

2) Reduce input or Increase output ... feed less, skim more , WC more any combo of them to reduce the Nitrates


Tank should be good , i know when i was on holidays and my doser ran out of vinegar and i had 2 weeks left in the vacation , i came home to my nitrates in the 75ppm range when now that are less them .5 on the hanna now

Cheers man and good luck dont stress

[Animal-Chin]

Thanks guys, did 30 gallons and i think the biopellets have kicked in cause im down to 40 now. Never thought i'd say "down to 40" lol.

[tang daddy]

What Craig said is true which is feed less and skim more while using bp or some other sort, a larger wc will only displace the nitrates temporarily but it will slowly creep up again. BP takes awhile to build up before it gets going like a few months. If you can I would do another larger wc like 50% this should in theory cut your nitrates down even further....

[Potatohead]

Correct I would continue carbon dosing for at least another six weeks and then slowly back it down for the next month, unless your nitrate starts to go really low then maybe end it a bit faster and monitor for the next week to make sure the pellets are working.