40B for a Mag Only Tank?

[VR28man]

What size a tank would be big enough for one that only contains a Heteractis magnifica and symbiont clownfish?

I ask this not that I want to make a minimum size mag-only tank, but more that I want to explore and understand what kind of real estate/conditions you'd need for a mag-only tank, which would be helpful in planning a mixed reef. (that is, if a 40B were sufficient for a mag+clowns, it would then seem, therefore, that even if you have a 75G you don't have too much extra real estate, probably 12x18" more area, and like 5 inches on top, enough for a few large coral colonies and a few pelagic-type fish)


Anyhow, it seems the first problem is size. The common statement is that the mag grows to 50cm-1m (20-39 inches) in diameter. If you base tank size for sessile organisms on its maximum size, it seems that a 40 breeder (36x16x16) would be essentially enough for a fully grown one. (technically a 36x36x16 90 gallon square would be best, but that's a custom tank vice anything commercially available. I'm also not aware of any commonly commercially available tank that exceeds 36 in length and 36 in width)

Going from "wikipedia sez is 50cm-1m" to statistically significant real world data, this article surveys Mags IVO Ras Mohammed at the end of the Sinai. It notes the following:

- maginificas were found from 2-40m (on par with other parts of the Red Sea, the coral sea islands, and the Kona coast of Hawaii which have very clear water and which have been prime locations for the study of "mesophotic" coral reefs down to the 40-60m range). However, most mags were at 3-33m, with the 40m mag being an outlier. Those above 9m were small and fairly sparse, though "at 3m there was one very large solitary anemone exposed to heavy surge induced currents"​

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- of note, another survey up at Eliat (summarized here) showed BTAs growing in crevices getting ~100-700PAR, with most living in the 2-500 range (and thereby getting substantially less light than the surrounding water). I would assume that the mags are generally more exposed than the BTA, that the PAR measurements would be similar at this mag site compared to Eliat, and therefore it would seem mags take the full light levels, i.e. genereally 300-1000 PAR. (note: some allege that this is only doable with sunlgiht or MHs; I'm not sure T5s can go much beyond 300, and some allege that LEDs are too focused that they'll basically sunburn cnidarians much beyond 300 PAR). I believe this mimics anecodatal aquarium keeping experience: these need a lot of light, relatively,​

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- total area of each anemone ranges from 1000-7000cm2 (the paper has the actual formulae for the numbers)​

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-108 mags were solitary (though within 1-3m of other corals or nems), 82 were in clusters (I don't think we can take a cluster in this tank....)​

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- in addition to clownfish, pretty sizable schools of Dascyllus trimaculatus hang out near these mags.​

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- current and even nutrients are positively associated with conditions for this anemone. We can definitely mimic the currents, but the nutrients (beyond the occasional feeding) might lead to bad water quality unless you had a very thorough nutrient removal system. (and I won't get into the question "do we really need to feed our nems?" which is amply debated elsewhere)​

Perhaps this is because of the very clear water almost devoid of terrestrial and freshwater input. Simultaneously the location of this anemone assemblage renders it subject to several different, sometimes strong currents. The major currents pass in the surface waters up the Gulf of Suez and the Gulf of Aqaba resulting in upwelling of nutrition-rich waters from the deep waters of the Gulf of Aqaba. These currents pass by the anemone assemblage (H. Samy, personal communication). The nutrition-rich water is a trait shared with an H. magnifica assemblage at the Aldabra Atoll (Figure 1A) observed by Fricke (1979). The Aldabra assemblage was however situated in very shallow water (main part at 0.5m depth at ebb tide).

Anyhow, based on all this my hypothetical mag-only tank would be the following:

- 40 breeder (too small?)

- sump with ample sized fuge/chaeto/ato, skimmer rated for maybe 75 gallons, maybe even ozone?

- automatic water changes, doing maybe 1g a day?

- dosing other trace elements, KH, Ca, or Mg should not be necessary, especially at this degree of auto water changes

- probably a large piece of live rock that it can mount to along with several other pieces, on a shallow sandbed

- maybe around 100x flow? (two MP40s running on opposite sides in anti-sync mode, running at either tidal swell mode, or 2 hours of reef crest twice a day and then a gentler mode the remaining time)

- sufficient biomedia and GFO in the sump (though this would have to be carefully done to not strip all the nutrients out)

- a 175 or 250w metal halide (Hamilton tech bali or bimini sun)

Anyway, some thoughts welcome. Again, I'm not planning to do this, just am thinking this through because some day I might want a mag, and thinking about an optimal mag-only tank will help plan its place in a mixed reef.

#biotopereefideas

 

[gabrieltackitt]

Can’t answer any of your questions but definitely following along.

 

[Nemguy123]

You gotta take into consideration I’ve been doing anemones mags especially since I was a kid they’re my favorite anemone and the biggest thing with them I found to keep them super happy is a large water volume of clean water or frequent water changes I’ve gotten mags adjusted to captivity when I didn’t have access to cipro by doing constant water changes with reef water it has always worked well for me.

 

[Nemguy123]

So a 40 gallon tank could be perfect if it fits but maybe do a 40 gallon sump or a 25 gallon sumo so you have that 65-80 gallons worth of water and In my experience it could do great in there