My seagrass and macroalgae tank

[mujacko2002]

updates pls

[mujacko2002]

actually, i am planning to set-up a 75 gallon macro-algae with seagrass setup but i am taken aback with this very expensive lighting. Anyway, i hope you stay in the path of macros and seagrass because your tank is an inspiration to all of us planted aquarium fanatics.

[shikhyung]

very interesting. I wonder where you guys colllect those macro algea, never seen it at LFS. Shin.

[johnmaloney]

Thats the sweet stuff

[cdckjn]

Hi, any updates on your tank so far?

[cmpenney]

Does anyone know of a good place to purchase Halophila engelmannii?

I'm setting up a tank right and was originally going to go with T. Testindium but I've changed my mine now and am going to go with Halophila now. I'm having a heck of a time find a source though.

[polaravic]

[QUOTE=halophila;5218055]Hi all, this is my new 4' shallow tank dedicated to

Hi Halophila,

Your tank is what I am trying to accomplish. I noticed you do not use 'marine mud' I was told I needed this for the 'grass' to survive. It is growing very slowly - seems to be struggling. I am using two 10 watt plant bulbs I bought from a hydroponics store which is more than adequate for most macroalgae except Halamida (which grows rampantly in my main tank - I have even made a bit of money selling it to aquarium stores)

Polarvic (just joined Reef Central)

[graveyardworm]

To Reef Central
Polaravic

You dont need marine mud necessarily. What you do need is a mature sand bed, and plenty of light. The 10 watt bulbs are no way enough for seagrasses. Since the majority of nutrients in seagrasses are taken up by the roots directly som people have experimented with injecting nutrients and even iron directly into the bed. Not something I would recommend until you have a better handle on keeping reef tanks in general.

If you look at a mature seagrass bed in the ocean you'll see all the leaf litter that collects within the bed. Not to mention all the sand bed infauna helping to transport those nutrients to the roots.

What kind of seagrasses are you trying to keep?

[Alaska_Phil]

I've had a planted freshwater aquarium longer than I've had a reef. and the rule of thumb for freshwater plants is a minimum of 2 watts of fluorescent per gal, and no more than about 5. I would assume that a similar level would be needed for marine plants.

Phil

[graveyardworm]

Most seagrasses come from very shallow water, and can be subject to more intense light than corals.

Freshwater planted tanks that I've seen have IMO very low light. the water freshwater plants grow in tends to be much more murky than seagrass beds.

50 watts of flourescent over a 10g tank to keep seagrasses as an example is going to result in very slow growth and perhaps even death. In regard to reefkeeping throw the light watts per gallon out the window. Its all about PAR and how well you can push the PAR into the depth of the tank. Flourescent lighting aside from T5 and to some degree VHO is generally very low in PAR and doesnt have any push to get that down to the bottom.

Keep in mind that most seagrasses are going to require some water depth for them to grow.

If you havent seen it yet here's some reading.

Beyond the Refugium: Seagrass Aquaria

and http://www.chucksaddiction.com/zone1.html

[Plantbrain]

I was able to easily grow any seagrass at 200 micrmols at the tops.
450 at the surface using PC lights, a pair of 65 W over a 25 Gallon tank was plenty for any species, this is about 75% less than full sun. 10% at the top/tips.

I would suggest that this is much less than many coral growers use for cultivation.

Temp, Alkalinity, Ca. NO3 etc stability are larger factors.
I do not think muds are bad or good, depends more on the mineralization occurred and the % organic matter. Most old mature dirty sands should do and water column uptake can be done fairly easily. Too much organic matter, too much NH4 or PO4(well, up to about 0.4ppm or so) and you can get the dreaded diatom bloom. I stick with 5-10ppm of NO3.


I disagree with the Freshwater comments, this is neither true for Marine or Fresh systems, they vary. I've gone out to Pigeon Key and it was less than 20cm secchi depth, other days, likely 20 meters.........this was in the same week. It really depends, and the season etc. Plants and algae are fairly adaptable IME/IMO to lighting.

Rainbow springs has a freshwater range of 80 meters of visibility.
This is all year and for the last 500 + years. Pupu springs in NZ has some of clearest water in the world(so they claim). These systems vary marketedly and can be covered by algae and marl deposits which reduces the light coming in to the plants by an order of magnitude, self shading is also a large player. Unless you account for the other potentially dependent variables, light is rarely the only dependent variable in culture. Few can set up control references, let alone grow these plants well.

"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."

So you have to challenge your own perceptions/prejudices and see if they are indeed true. Many things are not what they seem, this is aquaculture and horticulture, it is NOT Nature. Nor does it imply that nature is "best" for culture.

Give that some good thought before thinking that research from the field is really what is best for aquarium management and culture. Lab results are not the same as field test, and the reverse is also true and applicable here: nor are field test/measurements the same as lab test.

Gotta try it and see. Even that does not mean too much if you fail.
Maybe you messed up something or overlooked something? Many do.

It's the successes that are the references for aquarist.
Then you test and look at those systems.

Failures? You keep trying different things you think might help until you get a success. Nothing wrong with starting with natural systems for a model either if that's all you have(most of us do), but be very careful on the meaningfulness of that.

Regards,
Tom Barr

[3D-Reef]

In the field,this study says...."the actual amount of light reaching the seagrass depth target of 1.7 m relative to the preliminary light requirement of 25% of surface light." (based on Morris et al.2002)
http://www.tbeptech.org/SeagrassProc...virnstein1.pdf

In the field and the lab,this study says that...."the present tank and field studies as well as previous ones (Dawes et al.1997) indicate that transplants should be exposed to at least 200 M photons m2 s1 or more of sun or artifical light using a 12 hr photoperiod."
http://www.tbeptech.org/SeagrassProc...s/185dawes.pdf

[Plantbrain]

Originally Posted by 3D-Reef

In the field,this study says...."the actual amount of light reaching the seagrass depth target of 1.7 m relative to the preliminary light requirement of 25% of surface light." (based on Morris et al.2002)
http://www.tbeptech.org/SeagrassProc...virnstein1.pdf

In the field and the lab,this study says that...."the present tank and field studies as well as previous ones (Dawes et al.1997) indicate that transplants should be exposed to at least 200 M photons m2 s1 or more of sun or artifical light using a 12 hr photoperiod."
http://www.tbeptech.org/SeagrassProc...s/185dawes.pdf

I see little/no comment on pH/Alkalinity/Calcium, a dinky little Whisper filter......not sure what is in the root tabs, does not say in the paper, nor tissue analysis for N and P in the tissue.

I d not think they can say what the optimal horticultural light is for this plant independent of other confounding factors.

What parameters should be in the sediments? % organic matter? Redox levels?

I went through some of the methods, but.........I'm left with a lot doubt we can say much about what is the optimal light for growth rates(where adding more light produces no more added growth), the LCP (Light compensation point) for this plants, specific to this species.

Nice study and good goals, but I do not think it answers our questions.
Maybe they needed to use more organic matter, do more frequent water changes, adjust Ca, Alk, etc.

Light is just one factor in plant growth, location of nutrients is yet another and their concetrations are yet another, then the entire CO2/HCO3 balance is a huge issue.

As you increase light, the demand rates for the Carbon and nutrients goes up as well. I do not see where that was accounted for anywhere or in any paper on seagrasses to date. Does anyone know of one paper that addresses that?

I know of several that do for freshwater macrophytes:

http://www.plantphysiol.org/cgi/reprint/58/6/761

Figure 6 is what you need for the seagrasses to make much comment.
If some other factor is limiting light gathering by seagrasses, then they will have to divert more allocation to that, than getting higher light use efficacy.

These other factors have clear dependence on light use.
I do not think the paper cited for seagrasses really gets at that issue.

You can measure what is out in nature all day, but it does not answer what is best for a given goal independently in aquariums for management.

Sans Jensen does it here:
http://www.int-res.com/articles/meps/94/m094p091.pdf

Here is a different species, but a much lower LCP.

another decent paper:
http://books.google.com/books?hl=en&...age&q=&f=false

http://resources.metapress.com/pdf-p...4&size=largest

These are more appropriate applied papers I think.
Try using LCP, LS, redox and other key word searches, I think you will fine more fruit for use in aquariums and hopefully get some good ideas about what light intensity ranges you need.

200? I just got lucky as it's fairly high.
But......seagrasses have far less CO2 than many FW systems, but plenty of HCO3. Still, most every plant I know, will prefer CO2 over HCO3 and if you enriched the system with CO2, you would expect large increases in growth rates.

For freshwater species, this is roughly 10-20X, or 1000-2000% more growth.
That changes the allocation of light gathering resources and the ability to use much less light as a result. Plant is basically not busy using resources/energy getting Carbon, so it can divert more to light gathering. We can also add nutrients and their location/s to this model.

Now you have put all 3 main variables together.
If the CO2/nutrients are non limiting and stable, then you have independence for the light. I've not used CO2 gas for Seagrasses....yet.
I did not find that it really helped with Macro algae.

Grasses? Perhaps.

Worth a try.

I think once CO2/HCO3 issues are addressed, and nutrients both in the water column and the sediments, then we can really look at light for aquarium seagrass much better.

200 micromoles seems like as good a starting point as any based on experience and research in aquarium cultures.

We have a lot of work ahead

Dang, I hate that.

Regards,
Tom Barr

[3D-Reef]

Thanks for the links,Tom!

In this study they find that the lenth of time,or the amount of light,needed for photosynthesis is reduced with C02 inrichment.http://www.plantphysiol.org/cgi/reprint/115/2/599

IME I have a mix of 3,40w NO,2-65w PC's,and MH lighting over My fuge.Under the NO and PC lighting,the grasses grow slow and sparce,however,directly under the 175w Mh there is a definite difference.The grass shows more biomass,in leaf length and shoot density,with the only difference being the light it receives.

In another study at LSI it was mentioned that .5% of organics in the sediment was considered a little low.A starting point?My research was to find out more about the composition of sediments.What I found is that iron was the most limiting factor in caco3 sediments,increasingly so with the higher amounts of organics.As organics build up,the bacteria were limited by the amount of iron.When iron (FeIII) was introduced/injected into the sediments,the bacteria used the oxygen,reduceing sulfide production,and increased release of DIN and DIP for use by the plants/primary producers.

How does a hobbiest,without a lux meter,go about figuring out what 200 micrimoles would be over their tank?

[graveyardworm]

I can say that I have kept seagrasses under overdriven 40w flourescent daylight spectrum tubes. I have no idea though what wattage they were pushed to. Nor do I know how much light was reaching the grasses. I do still have the fixture ( DIY ) and could replace the bulbs and do some light tests over the same tank. I now have access to a PAR meter as well as a LUX meter. I have done some experimentation with introducing nutrients to the substrate, but without any real documentation other than an observation that it didnt appreciably increase growth. The best growth that I have seen to date was under 175w MH 10k bulb with the tank set up skimmerless, and no supplemention of nutrients Ca, Alk, Fe, NO3, and so on aside from occasional water changes. There were a couple fish in there getting fed regularly. Unfortunately I wasnt doing water tests of any sort to be able to provide any useful info.

[flying_dutchman]

Does anyone know if this tank is still up and running? Would a window tank in SF be a possibility?

[Plantbrain]

Originally Posted by flying_dutchman

Does anyone know if this tank is still up and running? Would a window tank in SF be a possibility?

MBA grows Zostera in natural light, you can see it at the tops of the kelp forest displays and other displays they have. Much below about 6-8ft, it will not grow. The other tropical species can likely do fine with less.

SF is not much different, but it would need to be a south facing window and get full sun daily.

Realize that this species at MBA does get all the nutrients via the water column, since the rocks do not offer much nutrients SF seawater is pretty rich in upwelling nutrients, which is why we have awesome kelp beds.

All aquatic plants, Fw and marine can and do take the nutrients up via the water column, some can do roots as well, sometimes a lot, but all are opportunistic.

So both locations need to be focused on, good CO2/KH, currents, light.

Regards,
Tom Barr

[davebar]

I am wanting to do Shoal Grass and turtle grass, what substrate is best for this?

[mproia]

Originally Posted by davebar

I am wanting to do Shoal Grass and turtle grass, what substrate is best for this?

Hi Davebar,

I am looking to do a tank of just shoal grass. I will be using a mixture of mineral mud and Caribsea Arag-Alive Bahamas Oolite sand topped off with just a layer of the Oolite. Total depth with be 4-5" I have read that freshwater plant fertilizer tablets can be broken in half and pushed into the sand by the roots of the plants for nutirents. What I am struggling with now is what kind of lighting to use. The total depth of the water column will 8 inches at its maximum. Have you decided on your lighting as of yet?

Regards,

Mproia

[Gregory King]

Good day everyone,

I am currently doing research on Halophila ovalis in Japan, and after seeings some of your photos I was really impressed.

My problem as of the moment, is trying to grow Halophila ovalis in the lab. My main source as of now are frozen halophila sent by plane (from Okinawa) (since the lab is located far away from the sea). I've been trying to grow them for quite sometime now, but have yet to succeed. Is it impossible to grow frozen samples of Halophila? or are there some problems with my conditions (I'll list them up below):

Grown in an Incubator:
Light (16 hours) (2000lux) Dark (8 hours)
grown in 1L glass bottles without cap
Total volume of sea water (natural seawater) is 300mL
Temperature: controlled at 25 ºC

Nutrients:
Potassium Nitrate: 17 ppm
Potassium Phosphate: 7 ppm
CO2 is supplied via a gas tank

Add reverse osmosis water regularly as a water change (to 300mL)

I've grown freshwater plants before as a hobby, but am quite new to growing marine plants, any help would be much appreciated.

Thanks a lot

[Forrest3320]

Tank looks great

[mproia]

Originally Posted by Gregory King

Good day everyone,

I am currently doing research on Halophila ovalis in Japan, and after seeings some of your photos I was really impressed.

My problem as of the moment, is trying to grow Halophila ovalis in the lab. My main source as of now are frozen halophila sent by plane (from Okinawa) (since the lab is located far away from the sea). I've been trying to grow them for quite sometime now, but have yet to succeed. Is it impossible to grow frozen samples of Halophila? or are there some problems with my conditions (I'll list them up below):

Grown in an Incubator:
Light (16 hours) (2000lux) Dark (8 hours)
grown in 1L glass bottles without cap
Total volume of sea water (natural seawater) is 300mL
Temperature: controlled at 25 ºC

Nutrients:
Potassium Nitrate: 17 ppm
Potassium Phosphate: 7 ppm
CO2 is supplied via a gas tank

Add reverse osmosis water regularly as a water change (to 300mL)

I've grown freshwater plants before as a hobby, but am quite new to growing marine plants, any help would be much appreciated.

Thanks a lot

Hi Gregory,

I would think that freezing the plants for transport may be the problem here. I am not 100% sure of plant tissues but I know for other cell types that freezing causes disruption of the cell membranes. Unless glycerol or another cryoprotective agent is added to the buffer that the cells are frozen in the cells are destroyed. Is there anyway they can ship the plants to you overnight or use two day shipping and not freeze your plants? From what I hear this is the normal shipping times of seagrasses and they seem to do fine.

Regards,

mproia