I am in the planning stages of building a vanishing edge hot tub using block construction over a poured pad and was looking for some help and suggestions in the plumbing and overall design. I have extensively researched the matter and have come up with the following:
900 gallon main rectangular spa, 9-4 long weir with an inward facing edge 2-8 above the catch basin (to avoid shooting the water overflow out past the wall face). Catch basin is designed to catch 275 gallons of swimmer surge (25 gallons per person, 11 people) above the minimum operating level of 16 (100 gallons). Looking at pushing 4 gallons/minute/ ft over the edge for a total of 37 gal/min (about 1/8). Not looking for a sheet over the wier, just enough to get the vanishing look from spa side. Will have an auto leveler at the minimum operating level in the catch basin. Three pumps: jets, filter/heat, and edge. I am separating the filter/heat from the edge so I retain as much heat as possible while hot and dont want the edge. Problem is the initial cold shot when I turn on the edge. This filter/heat only option also forces me into adding a skimmer to the main spa.
Questions: Should I add a skimmer to the catch basin? Add a filter to the edge circuit? Are my assumptions accurate for flow and catch basin capacity? Is it OK to have the edge pump 2-4 above the minimum operating level of the catch basin to keep it centralized with the other pumps?
Any assistance would be greatly appreciated! Thank you in advance