Sudden nitrate drop off

[VexedTomb792]

So, my system has been pretty stable recently (last 12 months or so) all levels in the ‘green’ I suppose you could say, phosphates around 0.03-0.05, nitrates between 10-20ppm, calc, magnesium, KH and PH good, algae levels in the tank steady (just a small amount on the back glass for the snails and fish to pick at), cyano beaten back to just a few small red spots on 1 or 2 of the rocks. I do 20% water changes every 2 weeks using reef crystals and always test the day before (so I get a picture of the water quality “at its worst” before the change). last weekend I found a bottle of ATM colony marine in the back of the cupboard, unopened and in date, I was going to throw it out and recycle the bottle and thought well it won’t do any harm and tipped it into the tank, I followed the instructions and turned off the skimmer (it’s been off all week). This weekend is water change weekend and last night I tested as per normal and was shocked to see that the nitrate level has dropped incredibly over the 2 weeks (to 2.5ppm from 12ppm)with no intervention from me. I blamed a long week at work and bad testing so I retested all tests today. Nitrate is now 1.9ppm (and I did it 3 times using a Hanna checker and averaged the 3 results to get that). Now I don’t want to do the water change for fear of them dropping too low! I do not want Cyano to start taking over again. at this rate of decline nitrate will be zero before this week is out! I’ve read everything online and Colony contains no bacteria that breaks down nitrate so it can’t be as a result of me adding it right? Any advice on what I should do? Water change as normal or not? Skimmer on again or leave off? I’ll paste the test results below and all of them are as of this morning having tested everything multiple times. All tank inhabitants are happy, healthy, behaving, eating as normal and look great. Any advice would be great.

 

[KrisReef]

Picture of the tank and sump please.

 

[VexedTomb792]

Picture of the tank and sump please.

No sump and tank is exactly as per the build thread.

 

[KrisReef]

Nice, I am still waking up and didn't even think to check your build.

I think that you are going to have to start dosing nitrate or feeding more, or both. Once the tank gets a hunger for NO3 it can keep it at near zero without intervention. I feed heavy which drives up P but I think I need to start dosing nitrates also. (Too lazy to test, but the tank "looks" hungry.)

 

[Randy Holmes-Farley]

I agree. Feed more is a good first step. :)

 

[Troylee]

Feed more and or add some more fish!

 

[VexedTomb792]

Feed more and or add some more fish!

Love the idea of adding more fish! I mean it gives me an excuse to spend money “the tank is actually telling me to buy more fish love, I have to do it” :face-savoring-food:

 

[VexedTomb792]

I agree. Feed more is a good first step. :)

More fish???

 

[Randy Holmes-Farley]

More fish???

Same fish or more fish, but more food.

 

[Troylee]

More fish???

It’ll be fine as long as they’re compatible.. more fish = more waste! More waste = more nitrates. I don’t see many fish in your tank.

 

[VexedTomb792]

It’ll be fine as long as they’re compatible.. more fish = more waste! More waste = more nitrates. I don’t see many fish in your tank.

Royal gramma, 2 clowns, bicolour angel, sixline wrasse, firefish, 2 cleaner shrimps, 1 fire shrimp and 3 hermits (one is a monster):)

 

[VexedTomb792]

Same fish or more fish, but more food.

@Troylee @Randy Holmes-Farley Should I leave the skimmer off for now and hold off on the water change?

 

[KrisReef]

Love the idea of adding more fish! I mean it gives me an excuse to spend money “the tank is actually telling me to buy more fish love, I have to do it” :face-savoring-food:

Listen to her!

 

[Randy Holmes-Farley]

I would not turn off the skimmer. Dosing ammonia or nitrate is not hard if you do not want to feed more.

 

[VexedTomb792]

I’ll put the skimmer back on then, it’s been off for a week, hold off on the water changes and I’ll feed half as much again. I’ll report back in a week. Thanks all.

 

[VexedTomb792]

Listen to her!

So, I came back (because no one ever does and the answer is invariably missing from the thread) I followed everyone’s advice, turned the skimmer back on, got a new fish (regal tang) who is stunning and settled in lovely with the other inhabitants AND I’ve been feeding carnivore and algae pellets on top of the usual frozen mix. It’s coming up to 4 weeks now with no water change and I’ve just tested phosphate and nitrate. Phosphate has gone up ever so slightly (0.01) and nitrate has gone up by 2.4ppm. Thanks to your help I may have caught that in time.
@Randy Holmes-Farley should I resume with the water changes now?

 

[Randy Holmes-Farley]

So, I came back (because no one ever does and the answer is invariably missing from the thread) I followed everyone’s advice, turned the skimmer back on, got a new fish (regal tang) who is stunning and settled in lovely with the other inhabitants AND I’ve been feeding carnivore and algae pellets on top of the usual frozen mix. It’s coming up to 4 weeks now with no water change and I’ve just tested phosphate and nitrate. Phosphate has gone up ever so slightly (0.01) and nitrate has gone up by 2.4ppm. Thanks to your help I may have caught that in time.
@Randy Holmes-Farley should I resume with the water changes now?

Probably, yes. :)

 

[VexedTomb792]

2nd water change since I acted on the advice and it seems to be all settled (values not moved for a month). Nitrate sat happily at 10 and phosphate at 0.08. All corals, fish and nems looking happy. Thanks all.

 

[KrisReef]

Thanks for the follow back after the discussions. Glad that the system has hit stride again.

I must lightly chide you for a fresh image or two so we can see the new Regal. :smiling-face-with-sunglasses:

 

[VexedTomb792]

Here you go! Beautiful Dory.