Heavy bioload tank phosphate approaches

[Raphael Dalmeida]

Hi all,

I know there's tons of topics out there about this, and I've read many of them. Though the quantity of info and divergence makes it difficult to decide on a "best approach".

So here I am asking the forum, for heavy bioload tanks where water change is minimal and most of elements are kept through dosing.

What are the best approaches to phosphate reduction?

Below is some of my thoughts and questions on different methods:

1.GFO - Seems great at removing phosphate, however does remove desirable trace, if heavy bioload would it be difficult to keep trace to desirable levels?

2.Algae Refugium - Ok at removing phosphate, will reduce trace and other elements, although heavily skewed towards nitrate. Upon depletion of nitrate, phosphates won't decrease.

3.Carbon Dosing - Removes some phosphates? But mostly it will decrease nitrates. Not sure what ratio for N:P removal. Reefers can dose additional nitrate to balance. Aeration or anaerobic areas could influence uptake of nitrate?

4.Lanthanum - Effective at higher phosphate concentrations. Can have detrimental effect to livestock if not careful. Unsure of long term effects of dosing it (e.g. using it as management rather than once off).

5. aluminium based Media - rapidly deplete phosphate, also depletes other trace elements and will leach aluminium with time (pollutant).

6. Biological media - alternate between aerobic and anaerobic zones in sump (does this even work?).

Ok, that's what I understand so far. What works for you guys in the long term ?
What are the methods that are best for a heavy bioload, and what is the effort in maintaining.

 

[Randy Holmes-Farley]

I’m not aware of any way to reduce phosphate without trace element export, though the elements removed will vary by method.

1. I doubt it is hard to add enough trace despite GFO, but you may want to monitor by icp to know how much is needed.

2. I employ heavy use of macroalgae and I also dose ammonium bicarbonate.

3. I don’t expect this is the best way to go for phosphate without dosing N.

4. Lanthanum is effective for any phosphate level, but as you note, carries risks to tangs that seem unclear in cause and avoidance. I would not assume there is no trace element binding like GFO and aluminum (and macroalgae).

5. I don’t recommend aluminum due to release of aluminum. It will have trace element binding.

6. Not sure what you are talking about here, but don’t see how it will be a good phosphate reduction method.

 

[Pod_01]

1. I tried GFO and it definitely works, can be too effective at low PO4 concentrations so use less and check phosphate concentration often or you can end up with zero.

3. Carbon dosing with N source seems to works from my experience. I used TM NP Bacto Ballance to maintain PO4 and to feed bacteria… Cannot comment how quick or slow it is nor if it works in most or few cases.

5. I tried aluminum based media and it worked, after reading about potential aluminum issues I stopped using it.

I always dose trace elements with AFR or TM A and K elements and my ICP results always show some trace elements.
Certain ICP companies are always eager to sell additional bottles of elements to address perceived deficiencies .


Good luck,

 

[Raphael Dalmeida]

I’m not aware of any way to reduce phosphate without trace element export, though the elements removed will vary by method.

1. I doubt it is hard to add enough trace despite GFO, but you may want to monitor by icp to know how much is needed.

2. I employ heavy use of macroalgae and I also dose ammonium bicarbonate.

3. I don’t expect this is the best way to go for phosphate without dosing N.

4. Lanthanum is effective for any phosphate level, but as you note, carries risks to tangs that seem unclear in cause and avoidance. I would not assume there is no trace element binding like GFO and aluminum (and macroalgae).

5. I don’t recommend aluminum due to release of aluminum. It will have trace element binding.

6. Not sure what you are talking about here, but don’t see how it will be a good phosphate reduction method.

Thanks for the through response. Certainly gave me some food for thought.

I'm currently dosing lanthanum, I started with higher dose and reduce as my phosphates went down from 0.5 to 0.09.

I'm contemplating slowly switching to carbon dosing and more aggressive Macroalgae export with ammonium bicarbonate dosing to compensate for the N:P ratio in both export methods.
As I see my current phosphate decline I would reduce my lanthanum dosing.

Do you think this is a good method for long term nutrient management ?

My predicament is I have an emperor angelfish and a few tangs in my tank and feeding extra is the requirement to keep them healthy or not coral feisty.

If you don't mind me asking, what Macroalgae you use? And do you still use carbon dosing on top of your refugium?

One extra question hehe sorry lots of questions. I see there are dosing guidelines/tables for vinegar and vodka, would it be possible calculate how much should we dose additional nitrogen to keep at a desired ratio (so carbon dosing works effectively for both N and P).

 

[Raphael Dalmeida]

1. I tried GFO and it definitely works, can be too effective at low PO4 concentrations so use less and check phosphate concentration often or you can end up with zero.

3. Carbon dosing with N source seems to works from my experience. I used TM NP Bacto Ballance to maintain PO4 and to feed bacteria… Cannot comment how quick or slow it is nor if it works in most or few cases.

5. I tried aluminum based media and it worked, after reading about potential aluminum issues I stopped using it.

I always dose trace elements with AFR or TM A and K elements and my ICP results always show some trace elements.
Certain ICP companies are always eager to sell additional bottles of elements to address perceived deficiencies .


Good luck,

Thanks for the response pod, very insightful.

I'd appreciate If you could share some more info on,
What methods you currently use ?

Would you say you have a heavy bioload or heavy feeding?

Do you still water change? Or mostly dosing?

In your carbon dosing with N source, are you adding additional N source to your tank? And how you figure out your additional dosing per carbon dosing (e.g. vinegar, NP bacto balance, vodka).

 

[BryanM]

I'm surprised no one has asked what your heavy bioload is.

In any case in this scenario I think I would go for GFO (due to tangs), and dosing phosphate if GFO is too effiecient at phosphate reduction.

 

[Raphael Dalmeida]

I'm surprised no one has asked what your heavy bioload is.

In any case in this scenario I think I would go for GFO (due to tangs), and dosing phosphate if GFO is too effiecient at phosphate reduction.

I have 1 emperor angel, 1 orange shoulder tang, 1 blue tang, 1 bristletooth tang, 1 pacific sailing tang, 1 scopas tang, 1 lineatus wrasse, 1 cleaner wrasse, 1 anampses melanurus wrasse, 1 sixline wrasse, 1 carpenters wrasse, 2 clownfish, 1 mandarin fish, 1 Friedman's dottyback, 1 Swallowtail angel (female), 1 bicolor blenny.

Tank is 6ft, about 1000 litres.

Because I have heaps of corals (SPS dominated) and with my emperor angelfish I make sure I feed twice a day (so he stays a good boy). The feed consists of a thin square of prepared frozen food (mix of krill, white fish, fish oil, spinach, Kombu, Chaetomorpha).

The fishes are thick, and I like them looking healthy.

So it might not be super heavy bioload for some but my phosphate was 0.5ppm before dosing lanthanum. I could notice the SPS corals suffering and growth stalling. Now phosphate at 0.09 tank looks much healthier.

I have a reactor spare, would you say if I were to go GFO I can adjust the phosphate at effluent using a manifold valve ? To make it last longer and decrease phosphate slowly.

Thanks for your input.

 

[Miami Reef]

You can use GFO and lanthanum simultaneously. Not a lot of people know that.

 

[Randy Holmes-Farley]

Thanks for the through response. Certainly gave me some food for thought.

I'm currently dosing lanthanum, I started with higher dose and reduce as my phosphates went down from 0.5 to 0.09.

I'm contemplating slowly switching to carbon dosing and more aggressive Macroalgae export with ammonium bicarbonate dosing to compensate for the N:P ratio in both export methods.
As I see my current phosphate decline I would reduce my lanthanum dosing.

Do you think this is a good method for long term nutrient management ?

My predicament is I have an emperor angelfish and a few tangs in my tank and feeding extra is the requirement to keep them healthy or not coral feisty.

If you don't mind me asking, what Macroalgae you use? And do you still use carbon dosing on top of your refugium?

One extra question hehe sorry lots of questions. I see there are dosing guidelines/tables for vinegar and vodka, would it be possible calculate how much should we dose additional nitrogen to keep at a desired ratio (so carbon dosing works effectively for both N and P).

No, there’s no way to determine how much organic to dose to maintain any particular phosphate level or to lower a specific amount. Trial and error is the only way.

The plan sounds fine to me.

 

[BryanM]

I have a reactor spare, would you say if I were to go GFO I can adjust the phosphate at effluent using a manifold valve ? To make it last longer and decrease phosphate slowly.

I use a reactor, but with its own pump. I'd think a manifold valve would work as well though.

 

[Pod_01]

Thanks for the response pod, very insightful.

I'd appreciate If you could share some more info on,
What methods you currently use ?

Would you say you have a heavy bioload or heavy feeding?

Do you still water change? Or mostly dosing?

In your carbon dosing with N source, are you adding additional N source to your tank? And how you figure out your additional dosing per carbon dosing (e.g. vinegar, NP bacto balance, vodka).

Up to about 5 month ago I was carbon dosing TM NP BB and it worked well. My PO4 was about 0.15-0.3, all looked good.
Tropic Marin NP Bacto Ballance has N and P in it and I do dose Aminos or Ammonia as well, my NO3 tends to be below 1ppm.

I still do water changes, and my fish stocking is medium/ heavy.

About five months ago my PO4 started trending to zero, so I stopped carbon dosing and began feeding heavier and even dosing PO4. Corals didn’t look great, and recently my SPS started peeling. Turns out the titration kit must have gone bad and was showing zero.
Using Hanna tester (diluting 10:1) I’m actually at 4.5 ppm PO4. Now I am just waiting on confirmation from ICP lab.

On the positive I think I found my tank PO4 upper limit.

Anyways once the lab confirms my readings I will be using GFO with Lanthanum (still debating it but I have a bottle) and I am going back to TM NP BB.

 

[wickedxreef]

You can use GFO and lanthanum simultaneously. Not a lot of people know that.

Curious, what GFO are you running? What have you been able to keep your phosphates at? I'm currently running GFO and LC, but can't get my phosphates below .166.