Is nutrient dosing... inevitable?

[Alexraptor]

Since a few months back I'm battling dino's in my 25g coral-filled reef. I was making some headway with dosing ATI Nutrion N and P per the calculators instructions, but now both Nitrates and Phosphates have bottomed out again and the dino's are growing stronger, which means I will have to increase the dosing amount.

While no dinos have cropped up in my old 15g reef, the nutrients have now bottomed out there too for the first time, despite broadcast feeding once a day with coral foods and feeding flakes to my clown whenever he's hungry, so I'm now having to start dosing there too.

I feel like I feed so much in my tanks, but it never seems to be enough, compared to my first 10 years in the hobby which were a constant struggle against high phosphates. Is nutrient supplementation really inevitable with mature grown-in reefs? Crazy thing is these reefs have no mechanical filtration of any sort, no skimmer, no particle filter, zip. The only thing I do is weekly water changes, which I can't really get away from due to allelopathy.

 

[shwareefer]

The only thing I do is weekly water changes, which I can't really get away from due to allelopathy.

IMO carbon would do a better job than 10% water changes.

Is nutrient supplementation really inevitable with mature grown-in reefs?

I dose ammonia for nitrogen and ultimately nitrate, but I've never had to dose phosphate. Seems like people setup brand new tanks and already have a refugium then wonder why they have no nutrients (not saying that's you). So no I don't think it's inevitable if people start thinking about balance instead of gadgets.

 

[fish farmer]

I would consider my tank "mature" in the sense that some of my rock is 20 years old and still wet. Current system was started around 2010. Battled with high phosphates and GHA for several years, finally getting them under control around 2020, to the point where detectable with hobby kits, nitrate and phosphates were zeros....never saw dinos....never seen dinos at least the outbreaks that folks seem to have. I was running chaeto in a fuge at the time and that even slowed in growth.

I boosted up feeding which helped boost detectable nitrate and phosphates....and a bit more in tank algae.

I think my corals were doing better with zeros, at least the tank looked better. I only have softies and LPS in a 29 gallon and growth of the hardier ones seems to be the same regardless of nutrient levels.

 

[djf91]

I think mature systems tend to be safe from Dino’s, even when N and P become undetectable. Many mature SPS systems from the past that eventually ran into undetectable N and P and still thrived with no signs of Dino’s. My belief is that there are some species of bacteria that will outcompete Dino’s in these “low nutrient” situations. Just keep things stable.

 

[shwareefer]

I think my corals were doing better with zeros

We have to assume there is always nitrate and phosphate, it's just who's using them that matters. I would think a perfectly balanced system would not have any residual nutrients to measure.

 

[Randy Holmes-Farley]

We have to assume there is always nitrate and phosphate, it's just who's using them that matters. I would think a perfectly balanced system would not have any residual nutrients to measure.

But having some nutrients to measure indicates availability is ensured, while not having any to measure might mean they are too low to be meeting the tank needs.

 

[Alpha_and_Gec]

I think it's independent of tank maturity, but instead what you put in it. Two years of batting high nitrates came to an end as soon as I put in a fistful of chaeto and now I feed hundreds of shrimps and pellets daily. Depending on what/how much corals you keep I'd bet you need less. In the past this system had been very low in corals and macros, and only this year I started adding macros and sps.