I was snorkeling among wild corals recently. I was really impressed by the amount of flow they get. I was on the back portion of the reef (behind the reef crest) in two cases (Hanauma bay and Kapoho Tide Pools) with sea states of 3-4 on the other side of the reef crest (the back reef approaching the reef crest was quite a workout). The other two were fringing reefs (Honaunau and Kealakekua), with sea state of I think 3. Also quite a swim workout, especially since you need to kayak for an hour to reach Kealakekua's fringing reef.
The sheer power of the waves was, as always, quite something. The amount of water it poured over the corals (Porites lobata, Pocillopora eydouxi and damicornis) is, in aquarium terms, astounding, and the sheer overwhelming strength that it had to clear accumulated detritus, etc. amazing.
It wasn't a matter of "I think the waves were equivalent to 50X flow", which they might have been. It's the sheer raw power compared to the powerheads even in a tank with, say, 30-50X flow. In one, there's a narrow spinning motion. In the other, it's overwhelming and omnipresent, you literally cannot stop it, you just have let it push you 3-4 feet. (in particular, the "cable channel" exiting the reef at Hanauma had a good amount of surge, and I chose not to exit from the back reef to the outer reef this time in the fear that I might be pushed down on the rocks while I tried to exit).
[and yes, coral growth was excellent, at least of the shallow water/high flow Pocillopora and Porites species common in these areas. A little bit back, at Kapoho (which was the only place where the geography would allow an area of somewhat lower flow for coral growth), the Montipora plates were as usual out of control - hundreds, maybe thousands, of plates starting at 2-3 feet, and several plates over 6 feet in diameter. I wish the coral life overall was in better conditions, though; for instane, despite lots of new growth Honaunau was depressing, especially compared to previous times I've been there]
Anyway, anyone who's ever swam in the ocean are well aware of this. But, I think that simply calculating GPH flow may be going about it the wrong way.
It would seem, to match that effect, you don't need 1-2 powerheads of power 50X your tank size; you need 2, maybe 3, powerheads of say 30X tank size each, all together, synced to do various strengths of of flow, preferably in a wave pattern with about 8-12 second periodicity, going up and down throughout the day. You probably will never run them at full power; it's the combined power of them working together, synced, over a broad base that's the key.
That, it seems to me, is only replicable by automated control; requiring an apex, as well as a DC pump. Maybe the Tunze wavebox can also simulate this effect.
The sheer power of the waves was, as always, quite something. The amount of water it poured over the corals (Porites lobata, Pocillopora eydouxi and damicornis) is, in aquarium terms, astounding, and the sheer overwhelming strength that it had to clear accumulated detritus, etc. amazing.
It wasn't a matter of "I think the waves were equivalent to 50X flow", which they might have been. It's the sheer raw power compared to the powerheads even in a tank with, say, 30-50X flow. In one, there's a narrow spinning motion. In the other, it's overwhelming and omnipresent, you literally cannot stop it, you just have let it push you 3-4 feet. (in particular, the "cable channel" exiting the reef at Hanauma had a good amount of surge, and I chose not to exit from the back reef to the outer reef this time in the fear that I might be pushed down on the rocks while I tried to exit).
[and yes, coral growth was excellent, at least of the shallow water/high flow Pocillopora and Porites species common in these areas. A little bit back, at Kapoho (which was the only place where the geography would allow an area of somewhat lower flow for coral growth), the Montipora plates were as usual out of control - hundreds, maybe thousands, of plates starting at 2-3 feet, and several plates over 6 feet in diameter. I wish the coral life overall was in better conditions, though; for instane, despite lots of new growth Honaunau was depressing, especially compared to previous times I've been there]
Anyway, anyone who's ever swam in the ocean are well aware of this. But, I think that simply calculating GPH flow may be going about it the wrong way.
It would seem, to match that effect, you don't need 1-2 powerheads of power 50X your tank size; you need 2, maybe 3, powerheads of say 30X tank size each, all together, synced to do various strengths of of flow, preferably in a wave pattern with about 8-12 second periodicity, going up and down throughout the day. You probably will never run them at full power; it's the combined power of them working together, synced, over a broad base that's the key.
That, it seems to me, is only replicable by automated control; requiring an apex, as well as a DC pump. Maybe the Tunze wavebox can also simulate this effect.
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