Can someone please explain words like "Moderate or Low Flow" or "Medium Lighting"?

[miyzfrider]

As a newbie to the hobby, and trying to place new corals in my tank, I'm very confused by all the words used to describe placement, water flow and lighting intensity. I see words like "Moderate", "Low", "Middle or Bottom" and I just am not sure how those translate to my tank.

My setup currently is a 90 gallon (4ft) tank, with a Hydor Evolution 1400 on one side, and a Tunze 6105 on the other side. My return pump is a 600gph.

My specific situation is that I have a new hammer coral I just purchased as well as a new soft coral, which I believe is a kenya tree or similar. When I look online to try and understand their needs, I just don't know how those translate to my setup. At first glance, with both power heads running (aimed at the center of the tank at each other's streams) the corals appear to be moving pretty firmly and probably too much. However, I know the gph those two create, along with my return, are not anywhere as close to the max many people are using.

So do you just have to lower the flow in LPS and Soft coral tanks? If so, how do you keep detritus from settling and not staying in the water column to be removed in the sump and skimmer? Or does "Moderate" flow mean they can be in some stronger current, just not blown on directly by the power head? How do you then tell if the corals are experiencing too much flow or not enough?

Any help understanding these terms would be great! This is one aspect of the reef setup that I'm just so confused about. Thanks!

[Humuhumunuku]

Leather corals can handle a lot more flow than most people realize. The hammer will probably want a bit less though. I have a torch coral (same Genus as hammer) and it likes "moderate flow." What does this mean? Well it seems to enjoy the swaying motion from the MP40, though it is on the opposite side of the tank. I have a koralia near it that points right next to it, though not quite on it. If I direct the koralia directly onto the torch, it closes up. So give them the most flow they can handle without closing up all the way.

Lighting is a bit more ambiguous. "High light" is assumed to be metal halides or sufficiently strong T5s or LEDs. You can start a lower or moderate light coral near the bottom of your tank and slowly move it higher, seeing how it fairs. Too much light can bleach corals, but many softies will enjoy the high light as much as an SPS. I personally have seen phenomenal growth of a leather under a metal halide near the top of the tank. On the other hand, a friend of mine has several leathers under minimal lighting and flow, and they seem fine too.

Try pointing your powerheads in different directions rather than strait at each other. Setting up some sort of gyre flow may be beneficial.