How much flow is there in the ocean over a reef. With the addition of my new skimmer I up sized my main pumps was 12,000 LPH now its 17,000. So how do you know when you have enough or to much (besides the rocks flying around).
You'd be shocked how much current and flow there is over a real reef.
Several knots current that you can't even swim against, Gorgonians and soft corals getting bent in half.
Even in no current you can even feel a surface wave surge while at 30-40 feet down as you're lifted and dropped several feet in the swells' energy.
It also depends on the reef bottom geography. When the tide goes out of a "shallow" 30-50 foot deep lagoon that is surrounded by fringe reef, it can really get quite powerful. Open ocean reefs and wall dives are more ocean current dependant but it can still be very strong.
How much is too much in our tanks? If the polyps stay retracted for long periods, or if the pump flow or current is pointed RIGHT at a near-by coral, thats not good either. Corals seem to like more indirrect current flow, which lends to their feeding habits too.
Unless the flow is pointing right at a coral, I don't think you can really have TOO much current or flow in a reef tank, depending of course what type of corals you keep. Random flow is best.
Just a few thoughts from a reef keeping scuba diver.....
If it is for smaller pumps, I would go w/ a seaswirl, they are a whole lot cheaper then the motorized ball valves. Those things are pretty pricy at around $500. If you do want to spend a lot of money, the oceanmotions are pretty nice also
Ah yes, just like the search for the Holy Grail, the reef keepers' quest is for an in-expensive alternating pump/wave timer controller.
Guess my way to opt out of the quandary is that I don't switch my water flow, its constant other than swirling and its own randomness.
My 135 gallon reef is 6 foot long, 2 feet high, 18" wide. Right hand end of the tank is a big RIO 3100 blowing right to left along the front glass, on the left hand end of the tank is a big dual output JBJ powerhead with one nozzle pointing forward and the other pointing along the back wall. I also have my sump return blowing right to left. This basically keeps the whole tank flowing in a circular pattern with water in a constant clockwise motion.
I run a very very simple tank, no controllers, no wave timers, no motorized valves......my theory is LESS technology, MORE biology...
While scuba diving walls, or spurs and deep finger grooves in the reef, in many places the current mostly only flows in one constant direction. As long as the water column is flowing past the coral bringing fresh food and nutrients to it, I'm not sure oscillating and random water movement is needed in all cases. Sure some corals may thrive in that back and forth motion, but damn that is hard to SIMPLY replicate in a reef tank for a bullet proof failure free hardware solution.
I am running a Mag 18 with my SCWD. It just keeps on working. I am pretty sure I have three and half feet of hose before the SCWD. So I wonder if SCWD under rates their valves for protection. I have not heard of anyone blowing one yet. If you have I want to know please. I will probably sell that set up of Mag 18, SCWD and two J tubes that I have on my old tank. I am planning on running a Gate valve with a Dolphin 2100 to work new SCWD that is plumbed into my new tank. I was told my Sequence pump will be less flow because of the plumbing I have attached to it. But then 3800 gph and 2100gph @ 7ft together I should have enough flow for a 90 gallon tank. Hold on Betsy, its The Big one...
If your tank expands like a balloon...You may have too much pump.
I saw on reefcentral (rolleyes) where someone seized a SCWD due to too much flow through it. Makes sense to me as there is no adjusting the mechanism, as you increase flow the SCWD switches faster. There is a limit to how fast it can switch before it just doesn't work anymore. Maybe it's more than 1400 gph (I thouhgt that's what they advertise), but I would certainly expect an upper limit.
I think the biggest challenge with big flow is just what RockyHeap said....you don't want to blast coral, you want a lot of indirect flow. Tough to do in a tank that is square.
I believe ya. SCWDs sieze if they get too much water pressure.
I highly believe in wave makers. I myself saw a noticeable difference in tanks before and after wavemakers. I truely believe the corals grow better in alternating current. Is there such thing as too much flow, I do not know. I think the key word is alternating current. Just my two cents, I know that was 50 cents ago...
If youve ever worked on the windshield wipers on your car then you know how sea swirls work. But yes I'll start on a dual Dswirl system this week.
I'll try to get the motor ordered before the holiday. What size are you thinking? I was thinking about starting off with 600gph x 2 (cheaper pump).
Ok Don, I don't need anything significant at this time. I have the closed loop on a manifold in the back of the tank, and there is not much I can really do at this point about that. I just need a 1" model, for my iwaki rltx 30 I think it is flowing about 800gph