Mangrove Experiment - 50 Gallon tank

[davy182]

can't wait to see the results

[m2434]

Originally posted by RawFish

As a note, many people have carried out similar mangrove experiments with successful results as well. The variable differentiating each tank and it's independent conditions seems to be the ratio Mangrove/gallon?

Sounds good, the more data we can pool the better. I have no doubt mangroves are useful. I guess my questions are more along the lines of what type of setup is most effective. For example years ago people were claiming you needed exposed roots (i.e. not in sand) to maximize the filtration capacity. Also, are they cost effective compared with other methods.

Personally I love mangroves and would like to someday incorporate them into my setup regardless, but from a scientific perspectice a lot of question remain..

Of course however, I certainly appreciate data - thanks for taking the time to report it!

[RawFish]

Interesting, thanks for sharing, I see you are a scientist and I bet you appreciate experimental knowledge more than I do.

My roots are fully exposed, except for the ones that have dug their way into the pump inlet foam. This is my first setup with mangroves, so can't tell if this is better for nitrate absorption than having the roots in the sand... I guess the sand is better for the plant itself due to the nutrient-sink effect from accumulated sediments; yet it would make sense to say that they get less exposure to the water column, less flow of nitrates to be taken?

My mangroves came already with developed roots, they now measure from 3 to 5 inches. I am sure I wouldn't have these results with only mangrove seeds without roots; at least that's what some people share in this forum.

Thanks for sharing, I appreciate your comments.

[SimilanRocks]

Great thread.

I have used 10 mangroves in my old 60g tank. I believe they must be taking a lot out of the tank to develop think leaves and roots. But the result was not that good. I still got >25 nitrate. And I chose good skimmer with macro algae, over mangroves. My nitrate went to undectable after I got a good skimmer with out mangroves.

The main reasons were light & space. Mangroves need a lot of light. Bulbs and electricity cost can be considerable. I didn't know what to do when they grow too big, may be throw away and get new ones?

RawFish, your testing looks great. But I think testing without mangroves only first week can't tell all the different. I'd double the mangroves and see if it will get below 5. I don't think a few mangroves will make that much different.

eddybabyhd, how deep is the mangroves sand bed? It looks like 6"? With low flow normally that would create dead spot and sulfer problem. I'm curiuos if you have any trick to handle the dead spot. Maybe the mangroves make sand very clean?

[capn_hylinur]

Originally posted by SimilanRocks
Great thread.

I have used 10 mangroves in my old 60g tank. I believe they must be taking a lot out of the tank to develop think leaves and roots. But the result was not that good. I still got >25 nitrate. And I chose good skimmer with macro algae, over mangroves. My nitrate went to undectable after I got a good skimmer with out mangroves.

The main reasons were light & space. Mangroves need a lot of light. Bulbs and electricity cost can be considerable. I didn't know what to do when they grow too big, may be throw away and get new ones?

RawFish, your testing looks great. But I think testing without mangroves only first week can't tell all the different. I'd double the mangroves and see if it will get below 5. I don't think a few mangroves will make that much different.

eddybabyhd, how deep is the mangroves sand bed? It looks like 6"? With low flow normally that would create dead spot and sulfer problem. I'm curiuos if you have any trick to handle the dead spot. Maybe the mangroves make sand very clean?

I think you mean good refugium with macro

[capn_hylinur]

The question of whether or not you need to run a phosban reactor if you are running a fuge and or dsb with mangroves.
It was felt that there would be a point when the phosban reactor would be removing too much nutrients and starve off the chaeto ect in the fuge?
Any comments?

[capn_hylinur]

sorry here is the thread:

http://archive.reefcentral.com/forum...=&pagenumber=2

[SimilanRocks]

Originally posted by capn_hylinur
I think you mean good refugium with macro

I mean good skimmer, and fuge with macro. Macro helps with pods too and it doesn't take too much space.

Originally posted by capn_hylinur
The question of whether or not you need to run a phosban reactor if you are running a fuge and or dsb with mangroves.
It was felt that there would be a point when the phosban reactor would be removing too much nutrients and starve off the chaeto ect in the fuge?
Any comments?

There is a thread on chemistry forum about GFO leaching iron. Randy think the iron leaching may be more than enough for macro. I think it's good for mangroves too. I'm running GFO too, it doesn't seem to starve macro. But phosphate problems are different on each tank.

[m2434]

In theory phosphate could be a limiting nutrient and nitrate levels could increase due to low phosphate levels. However, nitrate is fairly non-toxic, but phosphate can greatly reduce coral calcification...

[capn_hylinur]

Originally posted by m2434
In theory phosphate could be a limiting nutrient and nitrate levels could increase due to low phosphate levels. However, nitrate is fairly non-toxic, but phosphate can greatly reduce coral calcification...

don't mangroves and cheato algae also consume nitrates?

I am a little confused here about how phosphates can reduce coral calcification--can you explain more

[m2434]

Originally posted by capn_hylinur
don't mangroves and cheato algae also consume nitrates?

Of course, but tehy also require phosphates, as doesanything else. If phosphates are the limiting nutrient, then nitrates can accumulate, and if nitrates are the limiting nutrient then phosphates can accumulate. They may also be other required nutrients such as iron, and if iron was low, then nitrates and phosphates could accumulate. Even carbon could theoretically be a limiting nutrient, althought this probably will not happen ever...

Originally posted by capn_hylinur
I am a little confused here about how phosphates can reduce coral calcification--can you explain more

Well, I don't think anyone really knows for sure. Phosphate can act similar to mg and disrupt the surface of calcium carbonate crystals, and inhibit further binding. However, I don't think anyone has yet figured out how the phosphate gets into the extracytoplasmic calcifying fluid.

This is a little old, but I don't think anyone understands it any better now...
http://www.advancedaquarist.com/issues/apr2002/chem.htm

[eddybabyhd]

Mine are probably in close to 8-10 inches of sand. The flow comes from a piece of PVC with several holes drilled into it blowing water horizontally across the mangrove stems. To be honest, the sand even moves a bit. Its not a huge amount of flow, but it is enough to keep the dead spots at bay. I dont really have an answer for the sulfur problem. Come to think of it, the sand has never developed black spots or yellow. Maybe the root systems are keeping a good bit of that from happening

[m2434]

What are yuou adding for mg? I know epsom salts tend to be very high in sulfer. Also fe can catalyze the reduction to hydrogen sulfide, are you dosing iron? Also iron can combine with hydrogen ulfide to produce black iron sulfide deposits in the sand...

You probably have seen this, but just in case:
http://reefkeeping.com/issues/2005-12/rhf/index.php

[capn_hylinur]

Originally posted by m2434
What are yuou adding for mg? I know epsom salts tend to be very high in sulfer. Also fe can catalyze the reduction to hydrogen sulfide, are you dosing iron? Also iron can combine with hydrogen ulfide to produce black iron sulfide deposits in the sand...

You probably have seen this, but just in case:
http://reefkeeping.com/issues/2005-12/rhf/index.php

try using Kent Tech-M for magnesium dosing rather then epsom salts. I have about 180 gal in the water column---I maintain alk of 9.6 and calcium 400 and mag 1300 with 90ml two part bionic and about 90 ml of Kent tech-m every two or three weeks. Thats not a big cost for balanced additives.

[RawFish]

________________________________________________
WEEK 6 - Mangroves were removed for 1 week
While feeding normally: Brine shrimp, Spirulina pellets and marine flakes.

Nitrates: >10ppm
Nitrites: <5ppm
Ammonia: 0
PH: 8.0
Spec. Grav: 1.023
Calcium: 380ppm


Observations: Nitrates raised to a point higher than expected.

Conclusion: Although the rate of increase in Nitrate concentration is not high, it is similar to the observed previous to the experiment, when there were no mangroves in the system. Having only 2 mangroves in a system of 50G did not fully deplete the Nitrates, but allowed the measurement and observation of a different slope in the Nitrate increase in time.
________________________________________________

[Randy Holmes-Farley]

How did you remove the mangroves?

[RawFish]

Pulled them out of the aquarium and place them in a jar, with water from the same aquarium.

[Randy Holmes-Farley]

So did they have roots into the substrate that disturbed substrate when removed?

[davy182]

it could have caused a little spike if anything, but with futher measuring of nitrates the trend should keep going up if the mangroves were keeping the nitrates down.

[Randy Holmes-Farley]

Yes, it would be nice to see more trend.

[m2434]

Again, I think it's a tough sell given that it's essentially a single subject case study. It would certainly be more convincing if they were left out as long as they were in. So, I would keep them out for 6 weeks to see if the trend is consistent. Multiple repetitions of such a sequence would be even better if possible...

[eddybabyhd]

I think on a small scale it is almost inpossible to accuratly measure the benefits. Thats kind of why I took mine to the level I did. No one can convice me that my mangroves do not provide benefit.

Although I am open to discussion

[kfick]

I never hear of concerns with the leaves falling in the water. Aren't the tannin's somewhat toxic for corals if they decompose? I'm guessing they'd be a little acidic too.

I used to have mangroves in a refugium where I was propagating mushrooms. A leaf fell behind a rock that I didn't see and almost all the frags died in about one day The ones that made it recovered after the trees were removed. The frags were downstream from the lil trees, so they directly bathed in the tainted water. Nothing died in the main tank, probably because it was diluted enough through the sump return.

Just food for thought.

[eddybabyhd]

hmmmmmmmm interesting, never had a problem here

[SimilanRocks]

Frags can die in many causes. A mangrove leaf may cause nitrate but I don't think it's decomposed that quick to be the cause. I have had more than one leaves in the tank before, corals were fine.

Originally posted by kfick
I never hear of concerns with the leaves falling in the water. Aren't the tannin's somewhat toxic for corals if they decompose? I'm guessing they'd be a little acidic too.

I used to have mangroves in a refugium where I was propagating mushrooms. A leaf fell behind a rock that I didn't see and almost all the frags died in about one day The ones that made it recovered after the trees were removed. The frags were downstream from the lil trees, so they directly bathed in the tainted water. Nothing died in the main tank, probably because it was diluted enough through the sump return.

Just food for thought.