Nitrate Blues

[HumuhumuFan]

My 75g has been up and running for several years now. I was travelling for work extensively in for a year but was able to clean the tank on weekends. During that time I had a massive outbreak of vermetid snails, but other than that the fish and corals did just fine. I added a bunch of bumblebee snails and over time the vermetids seem to be coming under control. My war coral is thriving and my red montipora is growing so well I routinely have to prune it by breaking chunks off. I do have a few other corals though that are just staying alive, but not growing at all.

I have been regularly doing 15 gallon water changes every week. I have been battling algae for a while, but most of it is just a mat of hair algae on the back wall that I just scrape and vacuum out. Long story short, I have been very lazy about testing and since the fish are doing well and the corals are doing great or maintaining I've been really lazy about testing. When I did start testing again it was not pretty - 0.0 ammonia and nitrite, but 40ppm nitrates! For the last 8 days I did 20g water changes every other day. I tested this morning and my nitrates are still 40ppm. The tank has no sump and I run a Reef Octopus HOB skimmer on it. Last week I added an in-tank refugium and chaeto but the chaeto does not look like it's doing well. I tried to get it to spin but the pump I have just blasts it through the holes in the refugium wall and pins it against the wall even on the lowest setting.

Between the bumblebees and natural die off, my CuC is has pretty much disappeared. All that's left as far as I can tell are some bumblebees and one big hermit crab. I'd like to add more but I'm worried the high nitrates will kill them. I have some extra Aquaclear HOB filters, thinking about adding one and running Seachem Matrix in it. Not sure what else to do.

I currently feed the fish Spectrum flakes once a day, frozen mysis 2x a week, and a sheet of nori every day. I have a 3" yellow tang, a melanurus wrasse, 2 black and white clowns, and one yellow-tailed damsel.

 

[Subsea]

40 ppm of nitrate is not lethal, aside from being fertilizer for growth.

First off, Chaetomorphy does not need to tumble. If it grows thick, manually roll it every few days.

Seaweed growth is not controlled by the most abundant nutrients, but it can be limited by the least abundant. Iron is often a limiting nutrient. Consider dosing ChaetoGrow

 

[bubbgee]

Slow coral growth might be because of phosphates, especially for SPS and LPS. I monitor ALK and PO4 currently to see if there's any issues with consumption. If there is, I will check if there's a larger uptake (good) or decreased uptake because of increase in PO4 (bad).

Your soft corals should be fine if you have any if not have explosive growth because of nutrients.

 

[Randy Holmes-Farley Verified Community Expert]

40 ppm nitrate is within my target range:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

 

[HumuhumuFan]

40 ppm nitrate is within my target range:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

Thanks for this. I went ahead and obtained the LR Hanna Checker and my Phosphate is 0.57. I will focus on that. We'll see how the macro algae does first and if no luck, I'll re-evaluate. I'm very reluctant to use chemical means, many moons ago I used Phophate-RX per the instructions and the next morning my healthy yellow tang was dead.

 

[Ziggy17]

I’m curious as to what is elevating your PO4. Based on your feeding regiment, I wouldn’t think it’s from over feeding. Are you getting a lot of CUC die off? Are you doing WCs with RODI or distilled water?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for this. I went ahead and obtained the LR Hanna Checker and my Phosphate is 0.57. I will focus on that. We'll see how the macro algae does first and if no luck, I'll re-evaluate. I'm very reluctant to use chemical means, many moons ago I used Phophate-RX per the instructions and the next morning my healthy yellow tang was dead.

Lanthanum is a problem for some tangs. I personally would not use it with a tang in the tank.