Not using schedule 40 hard PVC pipe is stupid. Flex pipe is easier to install and performs poorly for a number of reasons. One reason is that flex pipe grows/moves when under pressure and using it under steel is suicide for the pipe, especially if it rubs the steel or bridging. I used some flex for a short period of time and found out the hard way how poorly it fairs for concrete construction. It does have it uses. It is used a lot in portable spa applications where the fill around it is controlled.
Hard PVC plumbing that runs to the bottom of the pool requires a little more labor to dig a proper trench and use 90 and/or 45 degree ells to do properly. Also as note, there should be no more than 1 pipe under any standard main drain grate. I do like to put the waterfall suction lines in the wall at least 3' below the water level with 3' min between the paired suction lines. Drawing water from a sidewall can eliminate debris from being drawn into the pump as opposed to drains in the floor of the pool. Good luck.

Your building has no idea how hydraulics work. As GolfGeek said do not use flex pipe. Get yourself a new builder that at least understands basic hydraulics.

Well I can't switch builders at this point. Currently, I have 3 flex pipes in the pool that are running up through one of my two skimmers. One for the main drain, one for the waterfall pump, and one for the booster pump (which is for the jets in the Grotto and the Laminars). It sounds like you are saying that the waterfall pump should be side suctions (yes they will be 3 feet apart), But what about the booster pump pipe? Should I have PB also make them side suctions? Initially that was the way they were supposed to be, but I changed it to having them inside pool because I tought it looks better to have them in deep end rather than on the side. I aslo thought it would be a bit safer as less contact would occur with drains on bottom of pool than on side of pool. They are antivortex drains obviously, but I still thought ti was a bit safer in case anything went wrong with the drain covers.. Why is it bad (if I understood you correctly) to have more than one pipe in the pool?

Thanks a lot.

Please have your builder get rid of the flex pipe. It not only comes apart over time but it's made of cellulose which is good termite food.
If your line velocities for the pipes are calculated correctly than it doesn't matter where the suction outlets are placed but since it sounds like your builder is not that experienced in plumping then at least have him do the following.
Suction outlet covers are only rated for a certain amount of flow through the cover. They can range anywhere from 80 gallons per minute to 220 gpm depending on the size and brand. The reason GolfGeek said to never install two suction pipes under one cover is because two pumps will normally pull more gpm than the cover is rated for. Also covers are rated for less gpm when they are installed on pool walls. Typically by 20 gpm. You can't add the gpm of both covers and say it exceeds the gpm rating of the pump. If one cover gets blocked than the other cover has to take the full gpm of that pump at its highest gpm rating. For example. If you have a variable speed pump that can produce 160 gpm than you have to have covers that will handle that gpm by itself. If you have a pump that produces 220 gpm the same applies. I always do multiple suction outlets for one pump. Meaning typically I'll have four suction outlets for the spa pump or three outlets for a waterfall pump on the wall of the pool. The possibility of someone blocking two or three covers at the same time is pretty unlikely. That way I'm always covered. At least have your builder do those. It's not hard. Also make sure he does field built sumps and don't let him just stick the pipe up throught the steel than create a little cup around it when you Shotcrete. Hope this helps.

I'm not sure I followed everything you said. For my water fall pump he is willing to give me three side suctions. The reason i put in the contract I could get three instead of two is that I thought it may be safer (all three would need be blcokd to suction someone). I think you are saying that isa good thing. For my other pump (the booster going to the jets in the Grotto and the Laminars), he also put in the contract he would also give me up to three suctions for that pump. So I could get six side wall suctions (three for each of those pumps). It sounds liek you are asyign I should do that and get those Flex pipes out of the pool)., However, for the variable Speed SVRS pump I am getting, the Flex pipe is in the pool, and i don't think I can get him to change that or make it a hard pipe. But when you say have him "build sumps and don't let him create a little cup" I don't follow at all. Presently, the Pipe is laid under the steel (about 2 inches) and it comes up through Skimmer). See attached picture.

The three sections are a good thing. You already have prefabricated sumps so no need for field built ones. Have him bury those pipes in the dirt. You need to have 3" of Shotcrete above and below your steel with nothing inside of it. Those pipes create a weak spot in the structure and should be buried below the dirt. Also you had mentioned earlier about your builder using three inch suction lines but only doing 2" into to pool until it came up out of the pool. You never go from small at the suction outlet to big. You can go from big to small only. By going from small to big your creating more line velocity which is more dangerous and your pump will not perform as well.

Here is an example. The pipes are dug into the earth and there will be 3" of Shotcrete below my steel. If I have to encase any pipe in Shotcrete I always make sure my wall is thick enough to place enough Shotcrete around it. I have field built sumps and at least 2" of clearance of any pipe from rebar when it comes past the steel.

Thanks a lot for your advice. I asked my PB to bury the pipes in the dirt and also offered to pay more money to get a hard pipe in the pool instead of my 2 inch flex for the Variable Speed pump. But I doubt he will do either (as he is rushing to Gunite before this winter gets colder and before more rain comes and washes away more rocks and makes mud in the pool. At least there does appear to be two inches of clearance between the pipes and the steel.

Another question I have is there any concern with locating the Pool equipment about 45 feet from the pool (at an elevation slightly below the Pool)? Also, on my Sundeck, the steel is 10 inches above the base. In order to make it an 8 inch water depth, they will need to pour 14 inches of Gunite (10 inches till it reaches the steel and then another 4 inches). I have read that the steel should be in between the Gunite. Is there any issue with having 10 inches of Gunite, then the steel, then another 4 inches of Gunite?

Thanks

Suction outlet covers are only rated for a certain amount of flow through the cover. They can range anywhere from 80 gallons per minute to 220 gpm depending on the size and brand.

Here is a link that might be useful: Swim Right Pool

Do you have a picture of the sun shelf area showing the steel placement?