Phosphate & Nitrate

[library 112]

So I have hit two years in the saltwater hobby now and many years in the freshwater. I have read and learned a ton in these two years and never thought saltwater would be so much more advanced over freshwater, boy was I wrong. Any way I think my tank has hit a full stride and is looking pretty good but got a question on chasing those main two parameters phosphate and nitrate. Here’s my system:

112 gal cube total system about 140 gal
Radios g6 run at 45% and a fluva 30 inch bar run low and short for a little more spread.

Have a skimmer
Filter floss and filter socks
Reactor run carbon in bag gfo light table in it
Large algae scrubber
Close to 200lbs of rock
Two gyers on back for flow
Dose alkalinity
Dose micro factor 7
Dose once a week coral snow with red&yellow from algae barn

Parameters:
Ph 8-8.3
Alk 7.9-8.4
Magnesium 1490-1650 (always run high)
Calcium 460-480
Phosphate currently running .15-.17
Nitrates 18-25

I have a icp test out right now should have back by Monday

I chased for a bit rookie and all. But when ever I don’t chase my tank has run very high. Currently it’s been running at these parameters for close two four weeks and my tank is looking really good and all is growing. So long story short is that to high on phosphate. Worried I chase it bottoms nitrates barley takes out phosphate and I get algae or something else bad.

So just general thoughts for one still trying to learn

 

[rishma]

I think the parameters look fine. I recently dosed some extra phosphate because I had been running below 0.1. I boosted it up to 0.15 and I’m quite happy with that. Nitrate looks good too. I dose to keep mine above 5. I’d be happy with your levels.

The magnesium is likely test error. It usually is. Suggest you don’t bother testing it. Your ICP will give you a more realistic value.

I wouldn’t recommend dosing just alkalinity long-term. The better approach is to dose alkalinity, calcium, and magnesium in the proper proportions or to use a combined supplement like All-for-reef. Alkalinity, calcium and magnesium get consumed in proportion to each other. Dosing just one of them will cause an imbalance.

 

[BryanM]

I wouldn't be worried at all about your nitrates and phosphates.

 

[library 112]

I think the parameters look fine. I recently dosed some extra phosphate because I had been running below 0.1. I boosted it up to 0.15 and I’m quite happy with that. Nitrate looks good too. I dose to keep mine above 5. I’d be happy with your levels.

The magnesium is likely test error. It usually is. Suggest you don’t bother testing it. Your ICP will give you a more realistic value.

I wouldn’t recommend dosing just alkalinity long-term. The better approach is to dose alkalinity, calcium, and magnesium in the proper proportions or to use a combined supplement like All-for-reef. Alkalinity, calcium and magnesium get consumed in proportion to each other. Dosing just one of them will cause an imbalance.

Thank you for the info. I know ca

I think the parameters look fine. I recently dosed some extra phosphate because I had been running below 0.1. I boosted it up to 0.15 and I’m quite happy with that. Nitrate looks good too. I dose to keep mine above 5. I’d be happy with your levels.

The magnesium is likely test error. It usually is. Suggest you don’t bother testing it. Your ICP will give you a more realistic value.

I wouldn’t recommend dosing just alkalinity long-term. The better approach is to dose alkalinity, calcium, and magnesium in the proper proportions or to use a combined supplement like All-for-reef. Alkalinity, calcium and magnesium get consumed in proportion to each other. Dosing just one of them will cause an imbalance.

sorry posted before I could finish. I know those parameters are connected so makes sense to dose all.

 

[Randy Holmes-Farley]

Your current values are within my recommended target range:

Randy’s Thoughts on Nutrient Target Ranges

Thoughts on Nutrient Target Ranges by Randy Holmes-Farley Almost nothing in the world of reef aquarium chemistry causes as much discussion as selecting and maintaining ranges for nitrate and phosphate. Some aquarists want low targets, some want...

www.reef2reef.com

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.