How effective is macro algae at phosphate export?

[Subsea]

Let us do the math.

 

Assume a 29G Biocube with .25 ppm of phosphate.

 

I will use 25G of water in the tank.

 

25G X 8.34 lbs/G. X 16 oz/lb. X. 28.6 gr/oz equals about 120,000 grams of water. At .25 ppm we are talking about .03 grams of ortho phosphate dissolved in the water.

 

Macroalgae contains 1% of phosphate by weight. Three grams of macroalgae will export every bit of the

.25 ppm of ortho phosphate dissolved in this 29G Biocube. Three grams of Chaetomorphy is smaller than a golf ball.

 

Is macroalgae an effective phosphate export mechanism? I think it is.

Patrick

[GlassHouse]

Well, nice start, but your calculations and assumptions are too simplistic.

 

1. You measured the inorganic phosphate in your aquarium, but ignored the fact that there is organic phosphate in your aquarium. Hobbyists don't have any way to test organic phosphates, but it's still there, and it's the type of phosphate that is going to be readily absorbed by macroalgae also.

 

2. Even if we accept your calculations, In order to eliminate the phosphate that is in your aquarium you need to GROW a golf ball size wad of chaeto to eliminate the phosphate that is in your aquarium TODAY. As you are growing that algae, you'll also be adding more phosphate to your tank by feeding. You need to understand not only how much phosphate is in your tank, but also how much phosphate you are adding to your tank. Then you need to determine what size refugium you need to grow that amount of macroalgae on an ongoing basis.

[Subsea]

Too simplistic? To what purpose does it need to be complex? I am not writing a doctoral thesis. The calculation is accurate for inorganic phosphate removed. It does not portray an ongoing dynamics at all points in time of all nutrients entering and leaving all aquaria.

 

Perhaps you should write a thesis to show us your knowledge level.

 

You point about macroalgae absorbing organic phosphate is incorrect. Only true marine plants absorb organic phosphate thru their roots. Cynobacteria is capable of producing enzymes to convert organic phosphate into inorganic phosphate and then assimilate into the cynobacteria biomass.

Patrick

[Subsea]

With twelve display tanks totaling more than 1000 gallons, only one has a refugium/sump. All display tanks have macroalgae growing in the tank. With tangs grazing heavily on Caulerpa Paspoloides, nutrient recycling is the major player. With this fast growing macroalgae, it is difficult to add enough food into the tanks to measure nitrate or phosphate. The one tank with a sump is a 30G mud/macro filter on bottom and a 75G Jaubert Plenum with a 6" sand bed of CaribSea Florida Crushed Coral on top. This tank has been set up for twelve years with no water change accept when vacuuming the sand bed, if required. I normally stir the top 1/2" of substrate every day to feed the inhabitants.

 

I recently experimented with a kelp concentrate that has all nutrients required by macroalgae except phosphate. It fueled a nuisance cynobacteria outbreak over the substrate. Without a doubt, organic phosphate is tied up in the substrate. Once the nitrate levels were elevated, the trigger was pulled. I combined vacuuming substrate with the use of Chemiclean and was amazed at the quick response of clarity in tank and sand bed surface.

 

As far as test kits go, cynobacteria is the best bioindicator of phosphate. Hobby test kits measure inorganic (ortho phosphate). I do not measure phosphate anymore. If I have a need to know a number, I send my water samples to an agriculture lab which measures organic and inorganic phosphate for $11.

Patrick

[MikeTR]

I have enough chaeto in my fuge to fill two 5 gallon buckets and I have cyano growing on top of the chaeto. I'd say it's not efficient enough.

[spanko]

I agree with the effectiveness of macroalgae as an exort of phosphate only if the algae is harvested regularly thus removing the phosphate from the tank.

 

MikeTR i believe you need to trim your Chaeto. It should be tumbling in the fuge and thin enough so that light can reach the center of the cluster. I think this would help to eliminate the cyano growing on the ball.

[Subsea]

I have enough chaeto in my fuge to fill two 5 gallon buckets and I have cyano growing on top of the chaeto. I'd say it's not efficient enough.

 

Cynobacteria is very resourceful. It will use either organic or inorganic phosphate. It will also dissolve calcium phosphate which has precipitated out on rocks and substrate. Vacuum out the cyno and detritus from the substrate. Remove 75% of your Chaeto as nutrient export. The cyno can scavenge nutrients from your Chaeto.

Patrick

 

PS. Why such a large volume of Chaeto. Is it for pod culture?

[hockeyhead019]

Assume a 29G Biocube with .25 ppm of phosphate.

 

Patrick, just curious where you're getting the .25ppm of phosphate? I'm not disagreeing with any other part of the arguement just curious why you went with this value?

[Subsea]

Someone on the ARC EMERGY FORUM posted it for their tank

[brandon429]

http://www.nano-reef.com/topic/319561-refugiums-dont-export-nutrients/page-6?hl=%2Breefin+%2Bdude+%2Bphosphate+%2Brefugium#entry4178263

 

check that out! that thread was a pretty big paradigm breaker for that year.

[Subsea]

http://www.nano-reef.com/topic/319561-refugiums-dont-export-nutrients/page-6?hl=+reefin++dude++phosphate++refugium#entry4178263'>http://www.nano-reef.com/topic/319561-refugiums-dont-export-nutrients/page-6?hl=+reefin++dude++phosphate++refugium#entry4178263

 

check that out! that thread was a pretty big paradigm breaker for that year.

 

 

Thank you for the link. There are some knowed up people on the thread. I read enough to know I don't have the time to give it enough time. After I get a few projects out of the way, I will give it the consideration that it deserves.

Patrick

[supernip]

why are you so hostile to constructive criticism? He's right, your methodology is flawed

[Subsea]

why are you so hostile to constructive criticism? He's right, your methodology is flawed

Where is the constructive criticism? If your statement is constructive, then by all means, explain it better.

Patrick

[supernip]

Well, nice start, but your calculations and assumptions are too simplistic.

 

1. You measured the inorganic phosphate in your aquarium, but ignored the fact that there is organic phosphate in your aquarium. Hobbyists don't have any way to test organic phosphates, but it's still there, and it's the type of phosphate that is going to be readily absorbed by macroalgae also.

 

2. Even if we accept your calculations, In order to eliminate the phosphate that is in your aquarium you need to GROW a golf ball size wad of chaeto to eliminate the phosphate that is in your aquarium TODAY. As you are growing that algae, you'll also be adding more phosphate to your tank by feeding. You need to understand not only how much phosphate is in your tank, but also how much phosphate you are adding to your tank. Then you need to determine what size refugium you need to grow that amount of macroalgae on an ongoing basis.

 

Too simplistic? To what purpose does it need to be complex? I am not writing a doctoral thesis. The calculation is accurate for inorganic phosphate removed. It does not portray an ongoing dynamics at all points in time of all nutrients entering and leaving all aquaria.

 

Perhaps you should write a thesis to show us your knowledge level.

 

You point about macroalgae absorbing organic phosphate is incorrect. Only true marine plants absorb organic phosphate thru their roots. Cynobacteria is capable of producing enzymes to convert organic phosphate into inorganic phosphate and then assimilate into the cynobacteria biomass.

Patrick

[Subsea]

 

Glasshouse choose to lift himself up with his knowledge. It was not constructive, it was self serving and from my point of view patronizing. I responded in kind.

Patrick

[Subsea]

why are you so hostile to constructive criticism? He's right, your methodology is flawed[/

 

Aside from attempting to derail the thread, do you have anything constructive to add? Please explain the flawed methodology on nutrient export of three grams of macroalgae.

Patrick

[GlassHouse]

Aside from attempting to derail the thread, do you have anything constructive to add? Please explain the flawed methodology on nutrient export of three grams of macroalgae.

Patrick

 

It seems like you are the one that derailed the thread by making personal attacks.

 

Too simplistic? To what purpose does it need to be complex? I am not writing a doctoral thesis. The calculation is accurate for inorganic phosphate removed. It does not portray an ongoing dynamics at all points in time of all nutrients entering and leaving all aquaria.

 

I pointed out a simple, basic fact about aquariums that you didn't take into account. If you want to ignore that simple, basic fact, then you are free to do so. If you decide to ignore that fact, come up with false conclusions, and then post them to a public board, I will correct you. Deluding people with insane, incorrect, and blatantly false information serves no one's interest. Sorry if that hurts your feelings.

[Subsea]

It seems like you are the one that derailed the thread by making personal attacks.

 

 

 

I pointed out a simple, basic fact about aquariums that you didn't take into account. If you want to ignore that simple, basic fact, then you are free to do so. If you decide to ignore that fact, come up with false conclusions, and then post them to a public board, I will correct you. Deluding people with insane, incorrect, and blatantly false information serves no one's interest. Sorry if that hurts your feelings.

It does not hurt my feelings. It displays your arrogance. Where was the personnel attack? Suggesting you post your own thread?

 

Nothing in the thread title or original post implied a thing about refugium design. Yet, you choose to run with that concept. If you had been a little less haughty, my response would have been dampened.

Patrick

[Subsea]

It seems like you are the one that derailed the thread by making personal attacks.

 

 

 

I pointed out a simple, basic fact about aquariums that you didn't take into account. If you want to ignore that simple, basic fact, then you are free to do so. If you decide to ignore that fact, come up with false conclusions, and then post them to a public board, I will correct you. Deluding people with insane, incorrect, and blatantly false information serves no one's interest. Sorry if that hurts your feelings.

To clarify the facts. Are you saying that macroalgae absorbs organic phosphate?

Patrick

[Subsea]

http://reefkeeping.com/issues/2006-09/rhf/

 

In the link, Randy Holmes Farley discusses the phosphate molecule. In its organic form, phosphate is extremely complex. In this form, it is easiest removed via skimmer as DOC before it is broken down into its inorganic form as orthosphosphate.

 

In further articles on organic phosphate, he describes phosphate uptake by cynobacteria. In this process, the cyno demonstrates an adaptability difficult to comprehend. Thru complex enzymes, the cyno converts organic to inorganic. The chemistry is regulated by a bio feedback loop to control the process. Imagine that, smart bacteria.

 

As he concludes the article on organic phosphate, he hypothosyses, that in the distant future all of the earths organic phosphate will be deposited in deep ocean trenches. Not sure if he was completely serious or merely using an analogy to make a point.

Patrick

[masterbuilder]

Short answer..... In our small tanks, it not very effective. Pods do love it though.

[Subsea]

Pods do indeed love it. I do find they are more likely to graze on microalgae and biofilms which often cover macro algae surfaces.

 

As in anything, it depends on how much nutrient in and how much nutrient export out. I particularly like using macroalgae in display tanks. There are many gorgeous macros for this application. In tanks with tangs, it is a perfect example of growing your own food within the tank for nutrient recycling.

Patrick

[kriskristofferzen]

Thanks for posting this info. I just was reading his article last night. Cool stuff. I didn't realize the differences between exporting inorganic/organic phosphates via media/skimming. What macro is best for inorganic phosphate export? any ideas?

[Subsea]

As I have many macro grow out tanks, I have used a tumble culture of Gracilaria Parvispora (Red Ogo), that was heavily populated with amphipods to quick cycle a tank. The macro with pods was added to a 55G tank with a vertical loop current producing a tumble culture. Using CaribSea Florida Crush Coral as a coarse aroggonite substrate, I hoped the pods would inhabit the substrate before fish were introduced. I feed this tank heavily with 12 hour light cycle for three days. I then added 40 mollies to the tumble culture of macro with pods. Continuing to feed heavily, after three days, I removed macro.

 

The tank was being set up to be a display macro grow out tank and the mollies and pods were to be the janitors along with Drawf Cerith snails. Two weeks after tank start up, I inspected the substrate for hopeful pod survivors with 40 fish in the tank. To my surprise, large pods were feeding in the open with mollies. All were feeding on detritus and biofilm on substrate surface.

 

The lion lay down with the lamb.

Patrick

[Subsea]

Thanks for posting this info. I just was reading his article last night. Cool stuff. I didn't realize the differences between exporting inorganic/organic phosphates via media/skimming. What macro is best for inorganic phosphate export? any ideas?

Anthony Calfo wrote an excellant article on Vegetable Filters used in refugiums. If you want minimum maintenance, Chaetomorphy is hard to beat. Because nothing eats it, I do not use it. It does provide an excellent matrix for pod habitat and will compost tomatoes. I prefer fast growing Caulerpa for nutrient export and nutrient recycling. Ulva is another excellent fast growing macro that everybody eats, including people. It is the main ingredient in Nori.

Patrick