I am the resident spraybar/flow tinkerer around these parts when it comes to seahorses.
I think spraybars are very useful in that you can keep the food out of the rocks. This helps the food not to settle and rot, pick up pathogens which creates disease. It will also help you to feed less, and you can get a ridiculous amount of movement in a seahorse tank without bothering the seahorses at all.
This was one of my early attempts. For holes I used a nail and a hammer. Made a few hundred of them. I left a space for the pump, a Mag 9 to go under it and the spraybar was also a support for my rock to get the shape I wanted.
That one for how ridiculous it was, worked well. Since it was totally underwater there was actually not much head loss from the pump at all and it was very strong. It ran in a 65g tank, but I still used two Seios 820's to get the flow across the front of the tank, and a return from the sump.
Next was for a smaller thank and I went simpler.
Those bars are much smaller, painted with pvc primer to match the coraline that would grow, and the ehiem 1262 that powered them was external. So basically a closed loop spraybar. I could turn either side off or on. I designed it so I could clean it by turning one side off or on, but the flow was enough that it was unnecessary.
I ran the return through a flow accelerator, and still needed to run a koralia nano across the front. That tank was turning over at about 110x. For awhile I had two koralia nano's, but later replaced both with one Tunze, some type of nano mini thing that worked better for me.
This is the tank months later when the macro filled in. All that work painting the pipe too. Do you even see the rock?
I have done maybe 10-15, O.K. more like 30 tries with spraybars. I think they are best when pushed through the rock, as a type of rock support, to keep detritus and food from ever getting into the rock. The most successful tanks I have had have a lot of movement (let's not get started on my sps tanks movement) and IME I really think it makes a huge huge difference.
If your going to run it on a closed loop, make sure not to hard plumb it, and leave some slack in the connecting hose so you don't get the loud noise, or a cracked bulkhead.
If you have enough holes, you really can't over do the pump unless your blowing the rock over.
If your using a feeding dish, plan for where it goes, in relation to your spraybar so your current does not blow the food out of the dish (gee, now how would I have figured that one out.... LOL)
IMO a little spraybar at the top of the water to create agitation, ugly piece of crap and is not going to do anything to help you. It needs to go behind the rocks. If your just looking to increase surface agitation you will do far better with a bubbler (air hose) or a powerhead pointed at the surface. In most of our cases now a stronger return pump would do the job as well, but some still lack sumps.
Sorry to come in late with a novel, but I already did all of the experiments. . . you would not believe it . .. . you don't need too.
