Growing Seagrass

[framerguy]

I'd like to start a thread on growing sea grasses. I have set my 75g tank up as a seagrass/mangrove tank with a 6" bed of mineral mud/fine sand mixture. It has been maturing since June. According to my research, seagrasses need a mature substrate about six months old and six inches deep or deeper as well as intense lighting. I haven't found much info on just what "intense lighting" means in actual wattages. At the moment I have lots of mangrove propagules rooting in the tank. I put seven bunches of Oar Grass in the tank a couple of months ago knowing the sand bed wasn't mature enough but oar grass is much more forgiving than some other varieties. As I was told to expect, the greenery died but little new greens started to come up. Well, they have gone away now and I'm not sure why. I am wondering if it is the lighting. I have four 150w curly flourescent bulbs and four 65w Compact flourescent bulbs over the tank. I am thinking of replacing the CF with T5. Does anyone think that would be a good idea?

Is anyone else growing seagrass? If so, what are you doing to be successful?

 

[cbrownfish]

What type curly Q bulbs are you using? They have some designated as "grow" lights, others as "daylight", etc. You may try one that has a different spectrum. Maybe do one side with one style and the other side with a different one. See which one works better.

It sounds like you have plenty of light IMO. Is there anything in the tank that is pooping and creating nutrients/organics?

 

[framerguy]

Thanks Ron. The only critters in the tank are 15 astrea snails and numerous stomatella snails but the tank IS tied in with the entire system. I got bulbs in the 6500K range. They didn't say grow lights though. I wonder if the mangoves are taking up too many nutrients...I do have about 40 propagules rooting!

 

[cbrownfish]

First let me say that I am not an expert on the subject but I have done a bit of research in the past. I would venture to guess that you are facing too much competition with the mangroves. Mangroves can be bigtime nutrient hogs. In general, successfully growing multiple species of grasses, macro algaes, or mangroves all at once, can be very difficult without ideal/mature conditions. It is not uncommon for folks to try to grow Chaeto and Caulerpa together in an algae scrubber/fuge......most of the time they compete until one fails. Sometimes it is just a b*tch to get the "nicer" grass and macros to take hold.

IIRC halide or high intensity lighting can sometimes be counterproductive with these types of grasses. I can't imagine you lack light but a different type or spectrum may help. If it is tied into the system, then you should have adequate nutrients. The substrate could lack some maturity or mineral.

 

[cbrownfish]

You got me wanting to do this again! I considered it a while back but scrapped the idea.

 

[framerguy]

In general, successfully growing multiple species of grasses, macro algaes, or mangroves all at once, can be very difficult without ideal/mature conditions.

Tell me about it. I also have a turf scrubber hooked up and my algae growth is Very Slow in my algae refugium. I have actually taken out some of the screens so the scrubber doesn't take up so many nutrients. Maybe I need to remove some more?

 

[cbrownfish]

If your nutrients are low, you may be forced to pick one. My nutrients are fairly high, according to mister Cyano, so I added a scrubber as an addition to my macro refugium (Chaeto). If your algae growth is low in the fuge and you don't have much nuisance algae, then you may need to reduce your biological export to have more success with the grass. You could also try sending the dirtiest water to the grass first (directly from display).

 

[johnmaloney]

when the oar grass came back up again did it grow with a thin red line down the middle? If so you are low on nutrients. You can rapidly mature a DSB with those FW plant fertilizers that you bury -(Flourish is the name of the Seachem product). Whether this will be good for your overall tank depends on what you got in there, but it will be great for the grass.

 

[charlesr1958]

Tell me about it. I also have a turf scrubber hooked up and my algae growth is Very Slow in my algae refugium. I have actually taken out some of the screens so the scrubber doesn't take up so many nutrients. Maybe I need to remove some more?

I wouldn't do that, the seagrasses have little use of nutrients in the water and depend a great deal more on their roots for nutrient uptake. They are afterall true plants. Might this article give you some insights?

The Natural Reef Aquarium - Part Two

Chuck

 

[framerguy]

John, thanks for checking in here. The oargrass came back up in tiny green blades, I didn't notice any red lines. The new blades are gone now, I'm not sure what happened. The bed seems to be maturing more now, I see critters moving around in it where I didn't see any before but I think I will put some fertilizer in it. I will need to get back with you on another purchase. What would you recommend as my next addition/attempt. The sand/mud bed is about 5 months old.

Charles, That is a great article and why I am trying seagrass in the first place. I have read it many times. It was a small (or large) memory lapse that made me think of the nutrient issue. As for the algae tank, the growth is very slow. The caulerpa actually is dwindling and I really like that stuff. The halimeda is doing well. As far as my chaetomorpha growing slowly, I think I found the problem. I cleaned the scrubber last night and found a giant wad of chaeto growing underneath one of the screens in the trough. It was beautifully bright green!

Thanks so much Ron, John, and Charles for helping me out! I truly appreciate it.

 

[johnmaloney]

I wouldn't do that, the seagrasses have little use of nutrients in the water and depend a great deal more on their roots for nutrient uptake. They are afterall true plants. Might this article give you some insights?

The Natural Reef Aquarium - Part Two

Chuck

The fertilizers you bury add nutrients to the sand. They will also take nutrients from the water column though.

If the blades came back healthy, the next place to look is what might be eating them. When you get the chance post a stocking list.

 

[johnmaloney]

when you fertilize, don't be indiscriminate about it. test, dose conservatively, then test. You are trying to get your nitrate phosphate ratio to around 20:1

 

[framerguy]

John, when you say nitrate phosphate ratio of 20:1 you mean the nitrates should read 20? to 1 phosphate? I seriously have a problem because my nitrates are 0 and no matter how much I feed they don't go up. I haven't made it to get the fertilizer yet, hopefully I can do that tonight.

The only animals in the mangrove/seagrass tank are astrea and stomatella snails and copepods.

 

[plecosword]

subscribing

 

[yungreefer2410]

this a very informative. you don't need a cetain size refuge for this do you? would say a 10g work?

 

[framerguy]

this a very informative. you don't need a cetain size refuge for this do you? would say a 10g work?

I am no expert on seagrass either but I think it is the sand depth (6"+) and lighting (intense) that make it work or not. The size of the tank is not a factor. I have seen some quite small seagrass tanks.

I think I am going to upgrade my lighting over the seagrass tank. According to john my light is adequate for oargrass, but possibly not for manatee grass or turtle grass. I have two metal halide fixtures but no ballast. I think after Christmas I will order a dual 250 MH ballast and put those lights over the seagrass tank. (if anyone reading this has a spare dual or two single ballasts please let me know.) I am building a dedicated mangrove tank to accompany the other refugiums and will remove most of the mangroves from this tank. The MH lighting over the seagrass tank will also spill over to the mangroves but will be quite a bit above them so I don't think the light will be to much for the groves.

I have asked for seagrass from my wife for christmas so we will see what comes out of that. It is very hard to find.

 

[Luukosian]

I have a lot of success with freshwater planted tanks but only grow chaeto in my fuge but have a couple of ideas to throw out. I use fluorite in all my planted tanks its a iron rich substrate that increases the growth of root feeding plants quite a bit. I wouldn't imagine you wouldn't have much dissolution of the substrate into the water column because of the high ph we keep our tanks but not sure. Another thing some people do in planted tanks is use a layer of laterite in the bottom layer as well(although i think it contains some aluminum and other stuff we might not want in our tanks).

Not sure if this would be any better than the mineral mud but might give more space for root growth since it has a bigger particle size than mineral mud.

 

[reefmasta]

ive got a 30G fuge/sump on my 265, with halimeda, mangroves, calerpa, cheto, and grasslaria with some burgandy kelp. cheto and halimeda is my slowest growers and i have the mineral mudd in there about 1'' thick mixed with fine crushed aragonite to complete 3''. i use ferrion by brightwell aquatics its an iron supplement for systems with refugiums becasue of all the macro pulling the iron out to grow and robbing it from the zooanthelle in corals. so its overall a benefit for me in my systems =) my lighting is natrual sunlighting so i cant really tell you what type of light is the best. probally a grow light in the 6700K range. hope you can use some info! i love to share experiences.

 

[framerguy]

I finally found some Manatee grass and Turtle grass online and in stock. This isn't the time of year for it to be found onshore I guess but I found someone growing it. I ordered 20 turtle grass' and one bunch of manatee grass. I also ordered two more bags of sand to get the substrate a little deeper. I will order the MH ballast after Christmas unless I find the funds before. I also ordered two extra bags of sand to put in the Mangrove tank so I can get them out of the seagrass tank. They are going to shade the grass to much I think. Anyway, I'll post pics once my goodies get here.