Zero nitrates and phosphates isn't always ideal for coral health

[Florin6]

I've been re-evaluating my approach to water parameters, specifically the pursuit of 0ppm nitrates and phosphates. While we all agree that low nitrates and phosphates are ideal for SPS, I've come to realize that this goal can be counterproductive in certain systems.

In a system with low bioload, maintaining low nutrients is relatively straightforward. However, in a system with a high bioload, such as those with numerous fish, low nutrients can be beneficial. The key difference lies in the balance between nutrient availability and waste removal.

Many of the most impressive tanks I've seen have a substantial fish population. These systems often have low nutrient levels, but the fish provide a steady supply of food for the SPS. Simultaneously, the waste is efficiently removed, creating a harmonious balance.

Replicating this balance in a system with only a few fish is far more challenging.

[FlynnZ]

I've had a similar experience. When I first set up my tank, I had SPS with just a few small fish. Over time, I noticed my SPS colors were pretty pale. I realized I was stripping the tank of almost all nutrients.

I've since made some changes. I now run my tank with slightly higher nutrient levels - around 3-5ppm nitrates and 0.03-0.05ppm phosphates.

[finnleye]

Take a look at my last thread, think I'm in the same situation as you guys, seems that way to me.

[Zenoxar]

My colours were on point at those super low levels - .03 PO4 and .2-.5 nitrates. Still trying to get back to that sweet spot, but it's proving tricky.

[dirtbox]

My PO4 is undetectable on the low range Hanna meter, but I'm sitting at 15ppm NO3. Despite the imbalance, my SPS are thriving and looking incredibly healthy, which has me wondering if I've found a sweet spot for my system.

[FableRise]

I've been stuck at zero phos for a bit, and it's taken a toll - I've lost a few birdsnest and some montis. Biopellets can get pretty aggressive once you hit those low levels. I'm basically overfeeding my tank just to keep some nutrients in the water.

[reeledin]

I'm considering "undetectable" nitrates and phosphates might be a better term for me, rather than "zero". Zero is definitely not ideal, but I'm not convinced undetectable levels of NO3 and PO4 are beneficial either.

[oceanrift]

I've found that recommended amounts for GFO, Carbon, and Biopellets are way off the mark. Start with half the suggested amount, or you'll end up stripping your tank of essential nutrients. My SPS really took off when I removed GFO and Carbon, and cut back to a quarter of the recommended Biopellet dose. Refugiums are still the best way to control nutrients while promoting coral growth – in my experience, at least.

[Vitaly]

I'm still trying to figure out what to do when my husbandry is on point and I hit those 0 levels. Do you guys just up the food, and that's it?

[Florin6]

I'm still trying to figure out what to do when my husbandry is on point and I hit those 0 levels. Do you guys just up the food, and that's it?

Totally agree with you guys - it's all about finding that balance. I was stripping my tank of nutrients and my SPS were suffering. Now I'm running at 3-5ppm nitrates and 0.03-0.05ppm phosphates and it's like a whole new world. My colours are popping and my corals are thriving. I think the key is to not be too aggressive with nutrient removal.