(new edit to post Oct 16, 2015) Please share your thoughts - recommendations.

So, it seems I am going to rethink the brand and type of hose I purchased. [size is 1/2 inch ID / 3/4 inch OD]
 
I purchased Clear PrimoFlex Advanced LRT specifications state: DEHP Free - Phthalate Free - (I know these are plasticizes)

Seems to be most brands and coolant setups have had issues. - I keep reading all the posts about plasticize leaching and white residue inside of hoses, on OC.net

Several hours over several days of reading posts and there seems to be no "clear" winner for best hose, (pun intended)

Did I miss something??

These have been suggested by form members:

Is Tygon E-1000, simply the best hose for PC WC? $$$ /but if it works

XSPC FLX Tubing

If I have to ship the PrimoFlex Advanced LRT, back to Performance-pcs and eat the shipping & 20% restocking fee -so be it. 

I just do not want to repeat this, buy / return cycle and get it resolved.  Nor do I want to be changing hose every couple months and cleaning my blocks.
 
 
(first post)
Looking for help / suggestions on:  water cooling pump, reservoir, hose size & brand, fittings & best flow. - My first custom loop is in progress.
 
Build:  What I have.
i7-4790k @ 4.8Ghz+ with Swiftech Apogee XL waterblock (currently part of Swiftech H-240-X)
http://www.swiftech.com/H240-X.aspx

 
2-way SLI EVGA Titan X SC with EK-FC Nickel Acetal full blocks and Ek FC Terminal Triple Parallel (80mm spacing on MB)
https://shop.ekwb.com/ek-fc-titan-x-acetal-nickel
https://shop.ekwb.com/ek-fc-terminal-triple-parallel
 
Qt 2 - Alphacool NexXos XT45 full cooper radiators (360mm x 45mm, Dual oval rows) - [ have third 360 rad. if needed]
http://www.alphacool.com/...Full-Copper-360mm.html
 
Case: Phanteks' Enthoo Primo:  (plan to place one 360  rad. in bottom of case and one or two 360 rad in top of case)
http://phanteks.com/Enthoo-Primo.html
 
So, my choices seem to be:
 
1) Add Titan X SC, 2-way SLI to current Swiftech H-240-X with up to two radiators - (can this pump handle this much?)
 
2) Keep i7-4790K on Swiftech H-240-X; custom loop Titan X SC, 2-way SLI
 
3) full custom loop.
 
My request for help & suggestions revolve around the following: (need to buy)
 
What size flexible hose & brand / material would you suggest & why. 1/2 ID X 3/4 OD

 
What pump would you suggest & why.
 
What reservoir would you suggest & why.
 
Do you recommend separate pump & reservoir or combo units?
 
 
Type - brand - size - fittings would you suggest & why.
 
What flow path do you recommend? (Rad 1 = bottom of case) (Rad 2 = top of case) (may sandwich two 360 rads in top w/ or without bottom rad)
 
A) pump - CPU - GPUs (parallel block)- Radiator 1- radiator - 2 - reservoir
 
B) pump - CPU - Radiator 1 - GPUs - Radiator 2 - reservoir - [maybe two 360 rads in top stacked with fan between and below rads.]
 
C) other
 
I have been reading some good posts here and OverClock.net the last several days. 
 
Now I am looking for input, pearls of wisdom, experience, opinions. 
 
What to get, what to avoid, best practice, what you or someone else learned the hard way.
 
Thank you for your input.

rlb9682
Sandwiching rads doesn't work well at all so I'd forgo that. You're better off, cooling wise, with one bottom and one on top. 
The flow path won't really matter.
 
Take your time with this, plan it out beforehand it saves time later. Pay attention to the thickness of the rads and the fans you're using and that will give you the total space needed on top or bottom.
 
What to get? If it's in your budget, I'd get compression fittings. Brands...everybody has their preferences but I have yet to try any brand for water cooling that didn't do what it's supposed to. 
 
I would stick with distilled water and PTnuke only in your loop. 
 
Also, test for leaks before running any liquid through the entire system because you never know. The first pump and mod top I attached needed to be tightened a bit so when I tested it leaked but since I tested it by itself only my sink got wet; just an example. 
 
Personally, I don't like dyes and stick with colored tubing. The dyes look pretty, but they break down losing depth of color and create small beads that stick in the water blocks of the loops over time.  

Thanks for the help.  Distilled and PTnuke were the plan.  The older Cu version?  There is a second version of PTnuke, but just the fact that you needed to use more of it steered me towards the "original" formula. I have also read to avoid dyes - and the possible issues.
 
I have read the woes of not testing the loop.  Will have to figure the best way to test individual parts.  My original plan was to build and test the loop as a unit.
 
Sandwich rads was a reference to add a third 360 to the top; sounds like it is not worth the effort.
 
Thanks

owcraftsman
#1 ditch the swiftech 240x in total wrap it up in the original box and head over to the trading post. It will make someone very happy. Stop leaning and go for it.
#2 switch to Serial sli bridge from my experience it works better. Temps by card tend to be closer to each other but the top one will generally always be higher.
#3 Excellent choice for watercooling but stick with Alphacool rads or pay close attention the rad width with other brands in the Primo especially in the bottom.
#4 All the alphacool rads are compatible with a Primo in terms of sizing. It's best to limit top rad thickness to 45mm in push pull config or you may have trouble with the 8pin EPS and or mobo HS. With 120 wides not so much but with 140 wides it get tight. However I've used a 60mm thick 420 up there in my last 2 builds but things are tight and the motherboards were forgiving with out modifications. I use a Monsta 360 in push pull in the bottom because there is plenty of room for it so why not have the extra cooling power but high static pressure fans are a must with it and some don't like the noise level associated with it. The reality is all rads perform best with high static pressure fans so really there is no getting away from it. The choice of the 420 in the top was in part decided on because only had to buy a couple extra 140mm Phanteks to do push pull with it cutting cost and they perform admirably and quiet. I bought extra 140 led for 5 total 3 on top and two in the front to match the blue outside lighting.
#5 I highly recommend the D5 pumps they run cooler less heat dump in the loop, last longer and quieter too that the DDC pumps but they have a higher head pressure which is great for long run loops. I prefer the 5-1/4 dual bay pump/reservoir combos mainly for looks and space saving convenience but the aesthetics are lost in a case with a front door so I recommend what I use which is the Bitspower watertank Z Multi with D5 top adapter and a 250 or 150 mm tube for a reservoir both fit nicely in the Primo depending on where you put it.I can't say one D5 pump/tube res combo is better than another because I simply haven't experienced the others for reference but I've heard good things about he XSPC Photon reservoirs and there diameter size may be an issue with longer GPUs if you want to mount to the reservoir bracket included with the primo.

#6 For serious loops I recommend 1/2' ID and 3/4" OD plasticizer free tubing  Tygon is the best. This is highly debatable because water blocks are way more restrictive than nearly any tubing and aesthetically they are quit large which some find offensive but I prefer to buy low restrictive waterblocks and remain certain my tubing is never the issue.  
#7 Fittings are a mixed bag I generally use Koolance compression style fittings matte black due to cost and they have a wider variety of other option than some which make having all the same fitting somewhat easier but they are lacking in some areas like extension and rotary combinations which at that point I turn to Bitspower. If money no object the stick with bitspower fittings they got it all.  
#8 I would not worry much about flow path for heat issues because after a system has be running for a while the temps normalize and nothing will help it from there you are stuck with what you got however I would worry about filling and draining the loop which is where the alphacool rads make life real easy with their 5 ports. I would straight drop from one side of the top rad to cpu block and from the other side straight into the reservoir from there take the cpu to gpus and res or pump out to bottom rad letting GPUs dump into the other side of bottom rad for a complete loop. This way filling from the top two ports of the top rad is easy if you use a long drain tube off the 5th port of bottom rad and hold it higher that the top rad during filling to relive pressure build up. 
#9 Avoid fluid with dyes if you can distilled water and silver coil is all you need for a happy health system. If you must have color I used to recommend colored tubing but after several failed experiments none are really that good and most become laden with scale within the 1st year of use hence the plastiszer free tubing. However I'm having good results with EK ultra pure fluid which come in several colors. I was struck by how well it cleans up and even washes out of rags easily, clothes too, oops lol. I have my doubts it will stain hardware like most of the others but the bus is still out on that one.
#10 Finally for all the minor nuances of the Primo as well as other Phanteks cases head over to the OCN fan thread for same.
Hope this helps ;)

Vry nice, great feedback.  Your insights because you have used this Primo case in your own builds is priceless.
 
D5 pump was the way I was leaning; unsure of reservoir.  XSPC Photon reservoirs with built-in D5 got some medium results from the reviews I read; but, as standalone separate parts they were much better.  Also like the Photon uses metal frame and glass tube.
 
 
 
Many thanks for your insights.

Just a follow up I noticed you mentioned thin wall I suspect you mean 1/2x5/8. I would avoid thin wall especially if you have any tight bends they pinch much easier and the plastiszer free tubing pinches even easier than standard tubing of the same sizing not near as rigid.
Dave is right about the fittings but I like the looks of the compression fitting better so mine is an personal aesthetic choice.
I really like the look of the XSPC combo and  appreciate the glass aspect a lot too. The only draw backs for me were not being able to fill from the top and it's wide diameter otherwise I'd have one or two hehe :D
It's fairly common practice to test the loop before adding power to it's components. I fill the loop and hot wire a spare PSU then hook up the pump and several fans and some lighting to give the PSU a decent load so not to damage it and let her run over night to get rid of air bubbles, check for leaks and such. I will line the areas where leaks might occur with paper towels for protection too. A good way to get rid of air pockets is to rock the case back and forth side to side and front to back and I've been known to even invert the case for good measure. Major and even minor air pockets have been known to be a major cause of under performing loops.
Something else I for got to mention is spend your money wisely and you will be rewarded for many years to come. I have stuff I'm using that is 10 years old. So keep in mind it will be around for many builds to come.
I also forgot to mention fan orientation and the benefits of positive pressure setup. Low rate of dust accumulation chief among them. Basically the setup consist of more intake fans than exhaust 14 to 1 in my Primo build and all intakes are filtered. Go figure that.
I'll take a few pic of my latest Primo build which is still not complete but it may be helpful to you and give you a few tips. I'll even show you the cart I made for it to improve the intake from the bottom of the case. Give me a few to get back to ya.

Note the new glass and case stand below. The factory glass is the only real failing to the case and I had to replace it. MNPC is making a solid glass door which I want badly I just haven't broke down and bought it yet.

another view of stand 4 sticks of 1"x2" ashes hardwood screwed glued and painted and 4 casters I also used flat 3" "L" brackets at all 4 corners to add structural integrity. 

Still finalizing/adjusting the lighting but basically blue exterior and red and white interior.
White is to highlight the red features and not wash them out as the all red lighting I had before did but I may be switching to DazMode Darkside Dimmable LED strips vs the XSPC LED cables in pics.

Essential mod highlighted here IMHO for EK backplates sadly they trap heat from the VRMs but needed for appearance sake the two fans blowing directly at them provide active cooling. The mod is simple 4 spacers to hang bottom fan off drive cage where it attaches and help rigid aluminum 240x120 fan grill clear the support bracket above and secure the top fan. Dropped my idle VRM temps 3c and 10c load avg respectively.

This view shows how I get around using a 420x60 rad with the Primo. Note the fans are clearly below the top HS by a good 6mm. Fortunately the Phanteks case allows for mounting the 420 with at least 20mm of travel front to back. I move it as close to the front as possible and with the MSI mobo EPS connector being close to the IO panel there are no issues reaching the connection. If the mobo vrm heat sinks were any taller a 140mm wide rad would be out of the question.

You can see the full loop here except for the drain tube attached to the bleed port of the bottom Monsta.
Silver coil in tube res but EK-Ekoolant EVO Blood RED & Tygon E-1000 1/2" ID (3/4" OD) "Plasticizer Free" Tubing
Koolance Compression 1/2x3/4 fittings

 
Still working on the cable management :D and procuring some new cables but Phanteks cases make cable management a breeze with all the Velcro ties. Note the dual fan hubs. I was able to buy one off a Phanteks owner who didn't want it for postage. I for one love that I can buy the cheaper 3pin fans and have them voltage controlled by the PWM mobo signal which the hub does nicely. The only caveats are 11 fans max per hub, each hub must be connected to a mobo connecter with CPU PWM signal which many boards on have one 4pin with PWM signal fortunately the MSI Z97 Gaming 7 has two. The only other boards that I'm aware of that have more than one PWM header are the ROG boards. Lastly the single fan connected to the #1 port will control all other fans connected to the hub in terms of RPM so if using dissimilar fans use the highest rated RPM fan on that hub to avoid this I use all same fans on a single hub. 
Also note the SSD brackets that hold 2 SSDs each and Phanteks sells extras if you need one. I could easily add 3 more SSDs and 3 more hard drives to this set up. You can see the one empty bracket mid low right.

 
 Final note on fan orientation In this build I have 14 fans set to intake all are filtered with removable filters and one fan is set to exhaust the top rear fan. Beyond supplying coolest available air to rads, what this does is force all air out the case via any available opening, mostly back panel, via positive case pressure. Conversely if you did the opposite it would be a dust trap because all the openings that are not filtered would allow dust in which illustrates how positive pressure works. There are arguments for both ways but I've found this works best for me and minimizes trips to the garage with this behemoth for a dusting.
 
GL with your build  
 
 
 

Sounds like a good buy.
When you get it together be sure to post come pics, while my preference is not compression's, sometimes they really look awesome and I am not familiar with the ones you mentioned so I am eager to see them installed.

EVGATech_DaveB
Sounds like a good buy.
When you get it together be sure to post come pics, while my preference is not compression's, sometimes they really look awesome and I am not familiar with the ones you mentioned so I am eager to see them installed.

This is the tubing that I decided on and after several months it was in perfect condition: http://www.amazon.com/XSPC-FLX-Tubing-ID-Black/dp/B00N9HVPLY/ref=sr_1_2?s=electronics&ie=UTF8&qid=1436114412&sr=1-2&keywords=1+2+id+tubing
I checked it over real good when I installed the EK parallel terminal block on the video boards.

NOTE: PrimoFlex Advanced LRT specifications state: DEHP Free - Phthalate Free - (I know these are plasticizes)


Seems to be most brands and coolant setups have had issues. - I keep reading all the posts about plasticize leaching and white residue inside of hoses, on OC.net
 
Several hours over several days of reading posts and there seems to be no "clear" winner for best hose, (pun intended)

Did I miss something??

These have been suggested by form members:
Is Tygon E-1000, simply the best hose for PC WC? $$$ /but if it works
 
XSPC FLX Tubing
 
If I have to ship the PrimoFlex Advanced LRT, back to Performance-pcs and eat the shipping & 20% restocking fee -so be it. 
 
I just do not want to repeat this, buy / return cycle and get it resolved.  Nor do I want to be changing hose every couple months and cleaning my blocks.
 
 
 

I can't speak from experience since this was my very first watercooling loop and I just grabbed what Amazon had in stock. I just know what I saw when I was installing the terminal block and rerouting my hoses. I use Swiftech coolant mixed with distilled water. I have a silver coil but I haven't use it yet so it's just sitting here staring at me from my countertop.