Thinking of Starting a Seagrass tank........

[KingOfAll_Tyrants]

So two week ago my "pre-reef" tank (petco tank without a sump to learn the basics of reefing) completely crashed, and so I'm thinking about my next steps.

I'm not ready yet to get into a big (30g+) reef, I think. So that's gotten me thinking about various other ideas that I've had....namely my seagrass idea.

I've been doing some thought and research, and will start doing some more reading of the various threads here the hopes of getting this live in about two weeks.



Anyway, here's my tentative plan. Thoughts welcome

13" cube or a 20 gallon high/long (i have a stand for a 30 long that I'd put whichever tank on)

No sumps or overflows. (thermometer, etc. in the main tank)

Tunze 9004 DC skimmer (I have one sitting around) + small oxydator
Maybe about 10lbs of live rock

Two MP40s (have them sitting around. Will keep them on lagoon mode in very low settings

Light: Finnex planted+; 1x will be sufficient?

Tunze nano ATO.

Maybe a CO2 doser?

Seneye reef to keep constant watch on ammonia, co2/oxygen and ph, at least initially.


Half the tank will have about 4 inches deep, while another half will be about 1-2 inches deep. I'll place miracle mud and/or a (1 inch?) layer of eco-complete.(edited to add: it seems there are several products out there that do this - miracle mud, koralagoon substrat, mineral mud.... they probably would be better than ecocomplete, because they're made for marine fuges and are therefore more expensive...lol) That being said, if I can get appropriate wild substrate for seagrasses, that would be even better. (GCE's stuff was good last time, but I don't know if it's appropriate for seagrass)

In the deep section I'll try to raise Halophila seagrasses. In the shallower parts I'm going to try to raise several forms of macroalgae as quickly as possible.

Initial plants will be various forms of in-sand caulerpa species. C. prolifera (fast grower), paspaloides (fast), cupressoides (slow grower). I may also try gracilaria and ulva as fast growers, maybe on a piece of rock or somesuch. I may also try one of the in-sand halimeda species. (an LFS has a big strand)

I'll start the tank with a tailspot blenny and of course a substantial CUC (astrea snails, a few trochus, small cerinths and nassarius. In total aobut 12 inches of snails for the 20G. I will add a conch of some sort, and a few shrimps. Though I'd love a tuxedo urchin my previous experience suggests they might decimate whatever's on the rock?).

Once things get acclimated I may add a gorgonian, and a few more fish if I go with the 20G (lawnmower type blenny, PJ cards, and i very much would like a yellowheaded jawfish again)

I have a feeling I'll have to dose nitrate and phosphate, and maybe even carbon (vinegar? Vodka?)


Anyway, just some thoughts. Critiques/experience/suggestions most welcome!

 

[Michael Hoaster]

Sounds great!

With plants, you need no filtration at all. It competes with the plants. I've had good luck with CO2 injection. Your small tank won't support a conch. It'll starve.

If you want to save money on mud substrate, you can do what I did and use dirt from my own yard. An inch or two on the bottom, covered with a pretty sand. My grasses are happy.

 

[KingOfAll_Tyrants]

Cool, thanks. So you recommend then no skimmer or anything like that?

 

[Michael Hoaster]

If you are really going to grow some plants, you will struggle to keep nutrients high enough. So let the plants get all of it instead of making them share.

 

[KingOfAll_Tyrants]

Fair enough. Two questions from your experience:

have your two tanks been, in your opinion, low, medium or high maintenance tanks? I've done a bit of careful reading of various build threads (and am still working through reading many more threads), and the two I went through this AM (seagrass's on nanoreef from 15 years ago) suggests this can be a very high maintenance tank, in that for seagrasses (halophila)it's important to keep nitrates, phosphates, carbon stable (by limited dosing of each?) and therefore keeping pH and KH stable is also necessary.

 

[Michael Hoaster]

Generally I'd say my tanks were/are low-maintenance. I rarely do water changes, I have no skimmer or filter socks to clean. But I do drive my tank pretty hard, with high light and high nutrients, so pruning is required every week or two. Not driving a planted tank so hard would lead to even less maintenance required.

Seagrasses do appreciate stability, but because they tend to grow in less stable areas, they are pretty adaptable. If you want less maintenance, add fewer nutrients, to keep growth slower. Seagrasses are able to out-compete algae by being able to grow in lower nutrient environments.

 

[KingOfAll_Tyrants]

Cool, thanks. Pending the introduction of seagrass (limited by availability), I probably will introduce seagrasses gradually.

My tentative plan is to start with caulerpa, and maybe even other macro (gracilaria, even maybe a ball of chaeto), getting the tank going/cycled, and then adding seagrass as availalbe /removing macros as needed. (sort of like the Walstad FW planted tank method of adding quick growing plants first and then adding more delicate plants)

In your (and others?) experience, can caulerpa also grow fast enough, in ideal conditions to, out-compete algae?

 

[Michael Hoaster]

Absolutely start with macros. Get your feet wet. See how you like it. Love the Walstad reference! She inspired my yard dirt sand bed that is growing seagrass very well. I used Ulva as my fast-growing first macro. It competes well with the ugly stuff. I added chaeto to my Caribbean Seagrass Tank. I was never able to fully eliminate it. But this is your trip through the macro algae jungle…enjoy!

 

[KingOfAll_Tyrants]

Absolutely start with macros. Get your feet wet. See how you like it. Love the Walstad reference! She inspired my yard dirt sand bed that is growing seagrass very well. I used Ulva as my fast-growing first macro. It competes well with the ugly stuff. I added chaeto to my Caribbean Seagrass Tank. I was never able to fully eliminate it. But this is your trip through the macro algae jungle"¦enjoy!

Thanks, Micheal. Indeed, it will be interesting. I honestly was nervous because i was expecting to have to but a lot of stuff (CO2, reef monitors, new test kits, etc.) but talking about it with you and a local, I'm feeling a bit better.

I may just dose vinegar or vodka vice getting a CO2 setup.

 

[KingOfAll_Tyrants]

One last question: how deep a sandbed do you recommend? I was going to go with 4 inches or so, but I fear that i ought to go deeper?

How do you arrange the dirt? Do you just put it at the bottom of the substrate? (As the planted tank folks seem to do?)

Thanks! (I think I'm about ready to go. I'm trying to decide between a 13, 16, and 19 inch deep tank)

 

[Michael Hoaster]

Sure, four inches will work. You're doing one of the smaller grasses, right? The bigger the seagrass, the deeper the substrate. I kept Turtle grass (the biggest) in seven to eight inches, in the Caribbean Biotope tank.

Ideally you'd soak the dirt in fresh water for a month beforehand, but its not required. I used about half soaked, half unsoaked in my current tank. Throw it on the bottom, cover with sand.