10 Gallon Star Grass Lagoon
October 1, 2006

Seagrass tanks are starting to become trendy and I am interested in trying something a little different from my other marine setups. I have just recently started researching planted aquariums. I have virtually no experience with saltwater plants and very limited experience with a few hardy freshwater plants, so this will be a learning experience for me.

I figure that the experience that I gain during this contest might translate into a neat looking seagrass refugium someday (a bit different than the more typical ball of Chaeto). Also, I’m currently in need of a decent quarantine tank (as I plan to replace my Yellow Clown Goby); and this tank should fit that need well.

My planned custom setup is very close to the stock contest requirements (with the exception of using daylight/daylight spectrum bulbs versus daylight/actinic, and using two alternating powerheads versus one that is constantly on). While these modifications are relatively minor, I feel that both of them will be positive additions to my little seagrass lagoon.

I plan on performing a maintenance routine that is similar to my other reef tanks (utilizing water changes to: balance water chemistry, supplement beneficial elements that were consumed, and dilute unwanted/excess elements). However, unlike my reef tanks, I will pay particular attention so that the tank’s nutrient levels are not entirely depleted (possibly testing the seagrass refugium idea by using water changed out from my 40gal display).

I plan on providing a hospitable (but not deep) substrate. In addition, since I hope to avoid adding additional fertilizer, I will likely encourage NO3 (nitrate) production, especially as the grass becomes more established. This would be a 180° change from trying to reduce the production of NO3 in my other reef tanks. However, the growth of the seagrass will likely be limited more by CO2 (carbon dioxide) and light.

CO2 system
Since increasing CO2 lowers pH, I might not supplement CO2 (as managing pH would likely become more difficult). However, because the grasses will likely consume CO2 faster than it will be naturally replenished, I am going to leave this option open.

Lighting
From what I have read, the 20” (40W) Current compact fluorescent fixture should be adequate to keep most varieties of seagrass in a standard 10-gallon tank. I will replace the standard (SmartPaq Daylight 10000ºK/Actinic 460nm 40W) bulb with a SunPaq Dual Daylight 6700°K/10000°K 40W bulb to provide a more suitable light spectrum for the seagrass.

Substrate
In order to provide enough room for seagrass roots and rhizomes (often located in less oxygenated levels of the substrate), deep sand beds are typically recommended. However, by keeping seagrass with relatively shorter roots, I am hoping that this will be unnecessary (as I plan to keep the sand bed closer to 2”). Since I also hope to avoid adding additional fertilizer, I have decided to amend the Nature's Ocean Bio-Activ Live Aragonite Reef Sand (0.5 - 1.7 mm Diameter Grain Size) with Refugium Mineral Mud.

Filtration
I plan on using a Penguin BIO-Wheel 150 HOB filter for filtration and surface flow. I also purchased 3lbs of cured live rock from a LFS in the area. That’s not a lot of rock (just a third of a pound per gallon), but I will be keeping a relatively light bio-load. My thought is that the grasses will consume enough nitrates that I can start utilizing more aerobic bio-filtration (possibly from installing the bio-wheel and/or adding bio-balls to the HOB filter). I don’t currently plan on using a skimmer; however, this could change in order to: assist with gas exchange, increase O2 (oxygen), correct pH problems, reduce dissolved organics, and/or slow NO3 production.

Additional water flow
My research indicated that seagrasses prefer high flow. Two Maxi-Jet 600 powerheads (160gph each) alternating by means of a Natural Wave Timer] will supplement the HOB filter’s flow (bringing the total maximum flow to 310gph at any one time). Although the wave action is mainly for aesthetics, the motion might possibly assist the plants in utilizing CO2, O2, and other elements. I’m hoping that the Clown Goby, that I plan to keep, doesn’t mind the flow (they are known to like SPS, which requires high flow, so I’m hoping that it will be fine).

Heating
I will be using a 25W Visi-Therm Stealth Heater. I would prefer to keep the temperature between 75° and 78°, but I’m guessing that my lights and pumps will end up dictating the final temperature setting. I usually set my heater to 2° or 3° lower than the tank’s peak temperature (during the light cycle). I will likely keep an open top to encourage evaporation for cooling and gas exchange.

Tank
At 20”x10”x12”, the standard AGA 10-gallon tank’s height restricts the depth of the sand bed, as well as the height of the plant and coral species. However, it should still make an excellent test bed for keeping Star grass. Plus, a 10-gallon tank is a reasonable size to mimic a potential star grass refugium.

Plants
Star grass (Halophila engelmannii): This species does not send roots as deep as some other varieties, nor does is grow as tall. I think it looks good too.

Fish
A Yellow Clown Goby (Gobiodon okinawae): This fish will probably be moved to my 40 gallon breeder after the contest.

Coral
I plan to stick with Blastomussa merleti growing on the Live Rock.

Other Inverts
A shrimp, Hermit crabs, snails, feather dusters, and hitchhiker starfish will eventually find a home in my lagoon.


Entry photo:

Instead of a mature sand bed, I opted to amend 20lbs of aragonite sand with a gallon of Refugium Mineral Mud; however, I’m not too sure about it yet. I initially tried to layer it, but it got stirred up when I added the water; so I decided to mix it together. It is currently about an inch and a half deep, but I might still siphon off the top layer and add more aragonite on the top.

Just filled:


My project is partially to apply what I learn to a future seagrass refugium. Along those lines, I decided to house my tank inside my 40B stand. Plus, I really didn’t have a better spot for it.

In stand:

1.5" sandbed isnt very deep.. and i know its possible for stargrass to live with that depth.. but i think you should add a half inch.. also.. add some surgar fine sand.. not aragonite...

I have aragonite mixed with mud and the shoal grass seems to enjoy it. I agree, I'd add another half inch or so - but I'd add mud or oolitic sand, not your normal reef grade, like FF said.

Looks good. Hopefully more people choose unuaual setups for this contest than past ones. I like it.

Yeah, I’m thinking that I’d like to keep it around 2” if possible. However, it’s funny how deep an inch and a half sand bed looks when you are used to keeping them at a half inch or less. I’d like to use sugar fine sand if possible, but I was wandering if it would stay put in the high flow.


Thanks jeremai! Your 40B thread was probably the biggest reason that I started looking into seagrass. Most of the information that I have is from the SeaNursery; I’m even getting my Star grass from Sarah. It won’t be that flashy, but I’m hoping to get more out of this than a chance to win prizes.


I was considering trying it without mud, but then I felt that this would require a mature sand bed (I was even considering siphoning off my 40B’s substrate for use in this project). I like the look of sugar fine sand; but besides that, what advantages do you see with it, over aragonite?

seahorses!

Yeah, I thought about that too, or even a Clingfish or Jawfish. I still might go in one of those directions after I quarantine the Clown Goby for my 40-gallon.

Thanks, seabass.

I ordered from Sarah too; none of the Halophila survived the shipping. Not her fault, apparently it just doesn't ship well - but the Halodule survived shipping and switching tanks. It doesn't get much more than 6" tall, so you could consider that, too.

Are you planning anything else for an aquascape? Maybe a standalone rock, or some red macros to balance out all the green?

Congrates.......you just set up an refugium! Now and a reef in line with it and you got something

I like the idea, but I have one concern..... What do you plan to do at night??? PH swings, I would think, would be off the chart. Livestock, especially seahorses, would require something to buffer this. Skimmer on only at night? How else would you stabilize it?

I’ll keep that in mind about the Halodule wrightii; I wouldn’t mind some growing towards the back. I also picked up a 3 pound rock that I plan to put some Blastomussa merleti on (I have a red one reserved just for this project). However, I like the idea of a good amount of beach for the grass (which isn’t that easy in a 10-gallon tank).


Yeah that’s pretty much what it is. Darn, I knew I should have just entered a modified AquaClear 70 and called it a day.

This is kind of an experiment for me, but I will have a fish and coral too. I was actually intending to enter the stock category (no sump). However, after I was informed that my intended mods would make it necessary to enter my project in the custom category, I thought about setting up another 10-gallon sump for a separate reef. But I had a hard enough time explaining why we needed even one more tank.


I have the same concern; I’ve been thinking about the best why to handle this. I’m actually going to have to use test kits again in order to see how bad it will get (what a bummer). I’m open to the idea of running a skimmer; with the addition of a CO2 system during the day.

I’m also a little concerned about pH buffers. I’ve been using Catalina’s Real Ocean water and I’m afraid that I will have to switch back to a mix (that includes buffers). I’m going to try to avoid adding additional buffers, but I realize that I might need to give in and start dosing something like ESV’s B-Ionic Calcium Buffer along with B-Ionic Magnesium.

I actually thought some about this today.

First, I don't think a skimmer on a night only operation would be a good choice. My thought is, the water left in when not in operation would stagnate. Initially, I don't think it would cause any problems. But I fear, over time, contaminants, and some undesireable bacteria would build up. I could be way off base though.

As a possible solution, I thought dosing Kalkwasser nightly might help. Kalk replaces many trace elements, and helps to buffer. The D.O. level still would need to be addressed with any livestock involved.

I'll keep thinking....
(That can be dangerous!)

Yeah, I also think that running a skimmer part time isn’t a good idea; and it shouldn’t provide any more benefit than running it full time. I think that it might even be bad for the skimmer (at least make it less efficient or need more frequent cleaning), as there might be more buildup without the flow.

If I go with the skimmer, I will run it 24 hours a day. I wouldn’t think that the additional gas exchange would be a problem; it might even help keep the pH more stable. However, if I run a CO2 system, I will only run it during the day (when CO2 is in need); if not overdone, it should speed plant growth without dropping the pH too much. The CO2 would need to be shut down in advance of the lights to prevent excess carbon dioxide (and low pH levels).

Kalkwasser should help to keep the pH high, and might be a good solution; although, I have to admit, that I’m not thrilled about the prospect.

True, but I really appreciate the thoughts, as this is new territory for me.


On a side note, now that the water is clearing, I can see that the sand bed is roughly 2 inches. However, I’m still considering taking off the top and adding another layer of sand for looks and better buffering.

sweet! cant wait to follow this one!

Im curious to see how the mud looks once the tank clears up, because Im in the planning phases of setting up this tidal mudflat/mangrove estuarine type setup, and was thinking of using this mud amongst other substrates/sediments.

very inventive tank concept thats bound to score you extra points!

Thanks sandlot13!


Here it is all clear, but with about an eighth of an inch of silt on the top:


For the top layer, I decided to buy 15lbs of CaribSea Seaflor Special Grade Reef Sand from my LFS. While there, I picked up a Poly Filter and an ammonia test kit. I’m pleased to report that the test was negative for ammonia. Then I siphoned off the silt and added the Poly Filter.

I think the substrate looks better now:




Before I add the seagrass, I’ll think that I’ll take off about another quarter of an inch of substrate. Then after I add the plants, I’ll put in at least a half an inch of the new reef sand.

Yesterday I spotted an Aiptasia; so tonight, I added a couple of Peppermint shrimp to try to eliminate the problem before it multiplies. Since there is hardly anything else to eat in the tank, I figure that I have a better than 50-50 shot of success. I had planned on replacing them with a Fire shrimp, as I previously had a couple Peppermints that harassed some feather dusters. However, now I’m considering keeping them; we’ll see.

I also added a Stomatella Snail, a Hawaiian Reef Brittle MiniStar, and a couple of Asterina Starfish. Everyone seems happy so far. My grass is scheduled to come tomorrow or Friday, so I removed a little more substrate again tonight (somewhere between an eighth and a quarter of an inch) to make room for the top layer of reef sand. This made for another 25% water change.

Looks good. Good luck keeping the sand stratified - I never had luck; every time I planted something or took somehting out all the layers mixed a little more.

Thanks jeremai, that was my first experience too. I layered the mud, and then the sand; but after I added the water, half of it was already mixed, so I just mixed the rest. I figure that if I plant the grass, and then add the sand (and leave it alone); it will take awhile for the critters to mix it up. But like you said, I’m not sure that it’s possible to keep this from ultimately happening. Plus, I don’t really hate the salt-and-pepper beach look.

Initially, I considered mixing the Refugium Mineral Mud with black Tropic Isle Tahitian Moon Sand. However, it’s not aragonite; and I figured that I should try to take advantage of whatever natural buffering was available (even if it is only minimal). Plus, over time, people tend to complain about bits of rock and waste showing against the nice black sand.

There are even a few light sand colored choices of refugium type mud, like CaribSea Araga-Mud. However, I liked the idea that Mineral Mud had sediments similar to ‘coastal mangrove environments’.

For the top layer, grain size was a consideration. While I typically prefer finer grade sand; I was concerned that the flow would blow it around too much. Crushed coral is typically 2 to 5mm (which I normally consider too large). However, the CaribSea Special Grade Reef Sand is only 1 to 2mm in size, so it is finer than CC, but shouldn't blow around as bad as surger fine sand. I hope it was a good choice; I’m mostly concerned that it will be less hospitable for sand dwelling critters. Any last thoughts on if I should use it or not?

Hungry Peppermints
Peppermint shrimp have the ability to eat Aiptasia, but sometimes it isn’t their first food choice. However, since there was little else for them to eat, they have taken care of the small Aiptasia that I had spotted. Unfortunately, they also ate a couple of neat little hitchhiker feather dusters that came on the rock. In spite of that, I’m kind of fond of the little guys; so I’m leaning towards keeping them.

Plus they breed like rabbits - instant plankton.

pics pics pics!

As requested:




I’m kind of bummed about not receiving my Star grass this week. I’m still trying to find out what happened; however, I was moving kind of fast, and a little more waiting won’t be a bad thing.

I still haven’t added my powerheads as I don’t want the substrate blowing all over. Also, I have been running my tank without a heater (or thermometer); I will remedy that this weekend. It’s probably time to put the lights on a timer too (I’m thinking 12 hours a day after the grasses are in). I’m also surprised about how bright the moonlighting is, so I might put it on a timer too.

can you link me to where i can find this grass you speak of?

www.seanursery.com

Looks good, seabass - your sand is just like mine!

Yep, jeremai is right, it is coming from the SeaNursery.


Thanks jeremai. I see that Nature’s Ocean has a black aragonite sand that might look good mixed with Refugium Mineral Mud. Maybe I’ll try that next time.


Temperature:
I put on the thermometer this weekend. With just the Penguin BIO-Wheel 150 HOB filter running, the tank is 72°; add the lights, and the temperature climbs to 74°. I’m guessing the Maxi-Jets will add some more heat, but I’m waiting for the seagrass to arrive (and additional aragonite top layer) before I turn them on.

Seagrass update:
It turned out that a bag burst and, with security the way it is, it was sent back. So it is being reshipped this week. Can’t wait.

I'll keep my fingers crossed for you. Third time's the charm?

To be fair, this will only be the 2nd attempt. So far, Sarah has been very good to work with, so I have no regrets. However, I hope that the 2nd times the charm.

CO2:
My seagrass hasn’t even arrived, but I’m thinking that I’m going to have to at least try to supplement CO2. I know that I could do a DIY system; however, I’m thinking about getting the Red Sea Turbo CO2 Bio-System. Do you think that by shutting off the pump at night, that this stops the flow of CO2 or just the Venturi injection? Any thoughts about this system (besides you could setup something similar with just an ordinary 2 liter bottle)?

Are we talking Sarah from RC? Such a nice person! Good luck to ya.

Yes, it’s Sarah (Samala) from Reef Central. Thanks.

It's just a fancy DIY CO2 reactor. You'll get the same results hooking a 2 liter bottle to a powerhead.

If you could remove it from the powerhead at night, but still keep the powerhead chopping air. This would keep the PH from dropping at night. Kind of a PITA, I know. But I really think all those macros asperating CO2 at night would be detrimental to any livestock.

never heard of seanursery.com, awesome site. i am really getting into macros

Thanks RayWhisperer. I’m still considering a DIY CO2 system; however, I’m going to attempt to make it so that I don’t have to fuss with it everyday. I’m thinking that nighttime O2 and CO2 levels will be alright if I can improve the tank’s gas exchange capabilities.


Tank setup left to do:
• Add a top layer of aragonite sand
• Install powerheads
• Install heater

I’m still trying to decide:
• If the Maxi-Jet 600 powerheads will be overkill (and switch to Maxi-Jet 400s)
• If I will use 2 powerheads on the Natural Wave Timer or just one
• If I will try to promote gas exchange with a skimmer, an airstone in the filter, or simply rely on flow


Thanks for stopping by travisurfer. Yeah, Sarah has lot of great information on her site. Speaking of the SeaNursery, my seagrass arrived this Friday (the 13th). They lost a good portion of their leaves during the 3 day transport, but I have hope that they will recover.


Here’s the first look at the just planted seagrass:

very nice seabass. hopefully it will all come along. i eventually may get some different grasses for my 20H since the caulerpa will have to go eventually. its grown at least 7 inches within 1.5 weeks. my sandbed is only 1/2" so i think i will be slightly limited. i will have to research which species will thrive in my system without being as invasive as caulerpa.

Good luck with the Halophila - like I said, I could never get it to stay alive, and it was the whole reason I wanted grasses in the first place!

Thanks travisurfer, I think that keeping seagrass will be substantially different from keeping most macros; I sure hope that I can get some Halophila engelmannii established. Maybe this project will provide some ideas for your 20H.


Thanks jeremai. I sure hope they will recover, but I’m afraid that they don’t look very healthy. It looks like everything was packaged with care; but like you said, they are just poor shippers. I know that she is working on overnight shipping options; which, I’m sure, would greatly improve their survival rate.

Seagrass update:
Unfortunately, more of the leaves are gone, with no signs of new growth. However, it looks like one of the starter colonies still has a few leaves, so I have my fingers crossed that it might pull through.

Even if one of them survives, I’m thinking that I will have to place another order. I want to be able to see growth versus laying down a mat of seagrass sod; however, I think that I will need a few more healthy plants to test the effects of the consumption of nitrate, phosphate, CO2…

a slightly rough start, but then again, thats what we get for shipping these plants and animals all the time! this is gonna be a really cool tank, i can feel it!

speaking of macros, is there anything not as invasive as calupera?? I have some in my 20L, and am looking for something that might just grow slowly and create almost a forrested look or jungle look?

Yeah, this wasn’t the start that I hoped for, but even these setbacks can teach us more about the hobby. Hopefully it will turn out well, but I plan on keeping it fairly simple. I’m more interested in experimenting with the tank than with winning the contest, but I still hope that everybody enjoys it.

Besides testing the concept of seagrass in a nano tank, I want to try a few things to see if I can apply them to a larger tank someday (with a seagrass bed on one side and a good sized reef on the other). I feel that a refugium can be as interesting as a display reef; and although it’s not an entirely new idea, I think that it would be neat to incorporate the two in a larger tank someday.

I’m not too sure about which macro would work best for you. Besides some hitchhiker macro, that I’ve done my best to get rid of, I have only keep Chaetomorpha. I’ve been hesitant to try other varieties for fear that they would go sexual. However, the more I read about them, the more I feel that this risk can be diminished by not allowing their nutrients to become depleted. You might get some ideas from WarEagleNR88’s stock macro project.

I’ve been thinking about a possible CO2 system lately. The Venturi CO2 injection system is proven; however, I’m not excited about putting another pump in the tank. During my research I came across someone who was trapping CO2 to improve diffusion. This was actually causing pH problems as too much CO2 was being introduced at night.

I was thinking that the above model could work, if it were to be modified to dilute and clear the trapped CO2 with fresh air. My thought is that I could put an air pump on a timer to accomplish this. In theory, the diffuser could be located anywhere (even inside the HOB filter).



What does everybody think? Would this work the way that I described?

You can run the CO2 tubing into the bottom of the intake (like drill or melt a hole in the side) of your HOB filter. The way the CO2 bubbles will dissolve as they rise, and they will get chopped up by the impeller. It works well with DIY CO2 and eliminates extra equipment, a lot of people do this in freshwater planted tanks.

I saw a thread, I think it was on RC, where someone was using DIY CO2 on a seagrass tank, and came up with a way to basically turn it off at night. It was some medical equipment I think. It basically was an electronic "T" that would take the CO2 line and vent it into the room's air rather than into the tank at night. I don't think it was expensive either, I'll try to find the thread.

AquaticPlantCentral.com and PlantedTank.net are good sources for information.

sea,
have you thought about iron dosing? i'm not sure if that was posted yet on the thread.

do you have anything grazing the epiphytic/film algae? i see shrimp but no snails. ceriths would do well.

Thanks, that's a very good idea. I just wish there was a way to automatically shut it down at night.

Reggae Reefer, is this it? Sarah is the one that I got the seagrass from. If I read the thread right, the medical equipment was to drip nitrate, and she was using a DIY CO2 system with a Venturi powerhead on a timer.

‘CO2 dosing continues, though is religiously turned off at night by shutting off the powerhead used for injection, via a light timer. A very simple and fuss proof system that has ensured no further green water outbreaks. I’ve also rigged a drip line for nitrate dosing, to make my life a bit simpler.’ - the SeaNursery

Cool, thanks, I will check them out!


I posted a link to an older article about on iron in reef tanks on WarEagleNR88’s thread. It sounds like it might have some real benefits (with a decent tolerance for error).

For the typical mixed reef, I have been promoting no dosing; however, I feel that this tank will benefit from added CO2, iron, along with alkalinity and pH buffers (including magnesium). While everything would likely survive without them, I think that it will be possible to improve their growth rate. After the contest, I will probably see how they do with just water changes.

Thanks tinyreef; you're right, I definitely need to beef up my cleanup crew! So far I’ve just robbed a couple of Stomatella Snails, Hawaiian Reef Brittle MiniStars, and Asterina Starfish from my 40-gallon. However, the algae on the rock is just starting to take off. I'm thinking about additing a few:
• Astraea Snails
• Bumble Bee Snails
• Cerith Snails
• Dwarf Blue Leg Hermit Crabs
• Nassarius Snails
• (and maybe one or two Trochus Snails)

Ok, Seabass. I asked my local planted tank club about how to control DIY CO2 with a solenoid, and one member came up with this:



It's so simple, it's genius. Basically the solenoid is install on a T inline with the CO2 line. When the solenoid is open, the CO2 doesn't make it into the tank due to the lack of pressure, it just vents into the room.

Here are some pretty cheap solenoids:

There's a used electronics parts supplier in the Bay Area that sells some for $4, you might want to check around your area for something like that.

That’s cool Reggae Reefer; a solenoid sounds like the way to go. Does that setup completely stop CO2 when the solenoid is open, or just substantially lessen it? I was thinking that it would be set it up like this (which would be a little less efficient when open, but it would completely stop it when closed):

I’d probably hook it up to the Venturi injector of the Maxi-Jet powerhead.

seabass, have you thought of using Flourish Excel? One mL treats ten gallons, and one dose a day is recommended - in a tank as small as yours, perhaps this would be an easier route to supplying carbon to the seagrass than CO2 injection...

I’m afraid to!

‘Dosed Flourish Excel (just to see what would happen). A micro star that had hitchhiked on the grass exploded.’
- Foxfire of Reef Central

‘DO NOT try this if you have organisms or you're dosing in the main tank (duh).’
- Foxfire of Reef Central

Hehe, see, I should've done some research first.