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Performance issues on custom loops

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rbn8rbn

New Member
Joined
Aug 17, 2020
Hello,

I recently made two hard-tubing custom loops (listed in loop order) :

1)
Bitspower Water Tank Z-Multi 400 V2
Bitspower Water Tank Hexagon 34
Swiftech MCP655 Pump
EK-FC970 GTX WF3
EK Velocity
Thermaltake Pacific TF1 (temp and flow sensor)
Bitspower in-Line Filter
Bitspower Leviathan XF 420

2) (same one without GPU)
Bitspower Water Tank Z-Multi 400 V2
Bitspower Water Tank Hexagon 34
Swiftech MCP655 Pump
EK Velocity
Thermaltake Pacific TF1 (temp and flow sensor)
Bitspower in-Line Filter
Bitspower Leviathan XF 420



I'm questioning myself about the performance.
On idle, i have about 30/33°C and 110L/H (about 29 GPH) at 100% PWM (almost the same on both loops, the one with a GPU had +3/5°C and -5/10 L/H).
From what i read online, the flow looks very (too?) low?
- Is that due to some component in the loop?
- Is that due to a faulty pump? Faulty flow indicator? (On both loops, that would be unlucky..)



Yet i had no temperature issues so i kept going like this for two months.
Last days, I emptied my GPU loop to make a tubing slightly different.

Yesterday, i refilled my loop and the performance got worse.
I have a 50 L/H flow (about 13 GPH!!), temp went a bit higher too (at 100% PWM).
I can't even flush the bubbles in the large reservoir.

Tried a few thing already, nothing helped.
I didn't empty the loop yet, this is probably the next step if i don't find a solution.
The loop is two months old, i don't think this is a dirt issue. Anyway i bought some distilled water to perform a cleanup.

I rather ask experienced people about this, because if i manage to get back to the nominal state (29 GPH), it still looks too low.
Does anyone have an idea? A diagnostic to perform?

Thanks in advance for your help.

Cheers.
 
Last edited:

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Welcome to the forum. Not real sure I understand your loops. Is this two separate loops or one loop that was built twice for testing purposes? Also why are you using two reservoirs with the Z-multi and the Hexagon?

I don't use the temp/flow sensors but from what I've read they aren't the most reliable when it comes to actual flow readings. Stack that on a Thermaltake brand item and I wouldn't trust it but that's just me. Since you said your temps were decent why worry about it? In all my loops I've never worried about flow rates, only CPU/GPU temps and never had a problem.

Also you said you can't get the bubbles out after the rebuild so that will impact performance without a doubt. What you see in the res is only a small part of the air in that system.
 

gregmacknass

Member
Joined
Feb 18, 2010
I second the sentiments towards thermaltake, but will also add this.

Thermaltake Pacific TF1 (temp and flow sensor)
Bitspower in-Line Filter

Throw both of these in the trash where they belong. If you flush the rads properly and avoid contamination a filter is not needed. Who cares what the flow rate is or the temp of the coolant (water).
These things are not necessary.

Make sure you bleed all of the air from the system. Rotate your case in every direction without drawing air from the reservoir into the pump.

If you get all the air out of the system, and your case airflow is good, then I would reapply thermal paste and try again.
 
OP
R

rbn8rbn

New Member
Joined
Aug 17, 2020
Thanks for the warm welcome and your concern about my problem.

It's indeed two different loops. GPU is my main computer, the other one a lab environment.
I added a second reservoir for aesthetic purpose, the first one is fully filled and the second (smaller) one isn't.

I can agree those sensors might not be very accurate, but that's too much difference to be the reason imho.
I bought these LCD to keep an eye on the system in case any issue happens. I rarely check my temps on my main computer, and i never will on the lab one.

Thanks for the advice about rotating the case. Unfortunately it is a deskmod, so rotation isn't a solution :D

I can agree that the flow isn't that important.
Reading stuff online, people usually recommend to set the PWM to get the flow rate at about 1.5 or 2 GPM (which makes about 450 L/H).
I have 10% of this, and i'm at 100% PWM. There's an issue for sure.

I can't even get rid of the bubbles, and i have a significant performance drop.
Considering the money invested, i'm a bit upset :D

I did a complete cleanup tonight.
When i filled the loop back, the flow rate was about 130L/H at start, and slowly (within 15/20 minutes) went down to 50L/H again...
That's weird.. Why would the pump slow down? I tried to set PWM to 100%, then to unplug the PWM connector, same result.
Could it be a pump issue? Considering my second pump has a 100L/H flow rate at 100%, it would suppose that both pumps are failing.

I'm starting to get out of idea, mainly due to my poor experience in watercooling.
Does anyone have an idea? A diagnostic to perform?

Thanks in advance for your help.

Cheers.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Flow rate matters, people! :)

That said, remove the filters. Not needed. Did you try another pwm header? Do the pumps flow properly without a rad and block? What rpm are they at? Res is before the pump, right?

Also, your pump is 1200LPH capable.


How about some pictures of your loop... :)
 

gregmacknass

Member
Joined
Feb 18, 2010
You are basing your flow rate off of a questionable device. Go read some reviews on this product.

https://www.amazon.com/Thermaltake-...tor-CL-W219-PL00BL/product-reviews/B07KR8VQQL
"Second: I am question the accuracy of the TF1. The Temp seems to be close but the flow meter is terrible. I have two Medium flow EK 360 rads and two high flow water-blocks and the most liters per hour the TF1 would indicate was roughly 180 Liters per hour. I have an EK D5 pump capable of 1500 Liters/hour and the visual observation suggests my flow rate was much higher than indicated. As a side note It can empty my 150 MM Reservoir in 3 seconds flat."

Like I said before, throw that garbage in the trash where it belongs. Bleed your loop properly to ensure all the air is out of it. Call a few friends over to help you rotate your desk around to get the air out. Or go buy a hand vacuum pump and a small fitting and vacuum bleed the system. And get rid of those stupid filters also. Post pictures as well.
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
I did a complete cleanup tonight.
When i filled the loop back, the flow rate was about 130L/H at start, and slowly (within 15/20 minutes) went down to 50L/H again...
That's weird.. Why would the pump slow down? I tried to set PWM to 100%, then to unplug the PWM connector, same result.
Could it be a pump issue? Considering my second pump has a 100L/H flow rate at 100%, it would suppose that both pumps are failing.
This sounds like all the air in the system to me. I would also assume it is fairly loud at times as well. As the air builds up in various points, including the pump and sensor it will cause the readings to go haywire and flow to reduce.

I agree with the above statements. Remove the filter and the flow meter. I know other pc forums swear by them but they are a waste if you properly clean the loop and use quality parts.

Flow rate matters, people!
Of course it does but I see no need to pay extra $$$ for a meter that may or may not work properly to monitor something like flow rate. Especially considering they are often so wrong and so expensive. They are just another gimmick put out by w/c companies to suck more dollars from inexperienced builders. No offense meant to the OP.

And yes please post some pics of the system to show it off! :D
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
I agree. For some reason it felt dismissed (flow rate)... but I get the point now. If you get decent ones, they'll give you a good idea of the flow rate... but they are not needed.
 
OP
R

rbn8rbn

New Member
Joined
Aug 17, 2020
Hello everyone,

Did you try another pwm header? Do the pumps flow properly without a rad and block? What rpm are they at? Res is before the pump, right?
- I tried PWM on my MB, external PWM, and unplugged PWM. Same results.
- I didn't test to run the loop with pump and reservoirs only. Hard tubes make the task harder. Gonna find a way and try it.
- PWM says pumps run at 4750 rpm.
- Yes the pump is right before the reservoirs. (cf. my first post, i listed them in loop order)


Also, your pump is 1200LPH capable.
I know, inside a loop with all blocks, you can expect 700/800 LPH.
Where are they :confused: :(



Gotta admit the reviews of the TF1 are a bit worrying. The leaks are definitely not wanted when my MB is right under it..

I hear all your messages about the filter. But when i cleaned the loop yesterday, the filter wasn't perfectly clean. I'm still questioning if it's not a good thing to keep it around.
I expect those wastes inside it were tube parts when i cut them, even if i obviously cleaned them before install.


This sounds like all the air in the system to me. I would also assume it is fairly loud at times as well. As the air builds up in various points, including the pump and sensor it will cause the readings to go haywire and flow to reduce.
I actually thought it was the opposite, as i used to have 150 LPH at start, then it slowly went down to 100 LPH for 2 months. (air doesn't stay stuck for that long?)
Still hardly explains why the maximum flow went from 100 to 50 between the first two months and when i refilled the loop 2 days ago.

I get it that the TF1 is inaccurate and should perhaps display 400 LPH. Yet the TF1 already was faulty when it was displaying 100 LPH for 2 months.
Why would it suddenly display 50 LPH (and that value doesn't change from day to day)? Something happened and is worrying me ^^


If you get decent ones, they'll give you a good idea of the flow rate
Is this one any better ?
https://www.bykski.us/products/byks...safety-module-w-oled-display-black-b-tfc-cs-x



Well.. Now the long waited part... Here come the pics ;)
PS : Be understanding about the mess, it's still alpha phase :p

Main - Front : Main - Back : Lab - Front : Lab - Back :
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Nice looking setup there. I've always wanted to build a desk pc but never wanted to spend all the dollars to do it properly.

I get your concern on the filter but at best use it for a little while then remove it if you must. I would skip it in general on your next rebuild.

(air doesn't stay stuck for that long?)
It can, especially if you can't tilt and turn the case like you said you can't because it's a desk. Without properly bleeding it all out it will basically never go away because pockets will be trapped all over. A big bubble moves from the radiator to the pump and your flow will go to crap. Then it will move on to another spot and so on, and so on. I would find a way to to tilt the desk around if at all possible to get it all out. At the very least lift it a little then drop it to see if any air moves around. I'm always amazed after letting my system leak test on the bench for a day or so to find a massive bubble jar loose when I tilt it again.

Basically unless your pump is bad from the start it should stay pretty consistent, I've been using the same Swiftech 655 for many years with no problem so yours is either bad from the get-go or the flow meter is just crap. I would say it is the flow meter personally. The only way to check would be hook another pump up and see what it does.

Don't waste your money on any of them. If you want one just to make sure everything is moving then get one of the mechanical ones.
 
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rbn8rbn

New Member
Joined
Aug 17, 2020
Hello and sorry for the late reply.

Thanks for the compliment, appreciated :)
Yeah it definitely cost a bit :D I decided to keep my old computers.

Well the desk weight a lot and it took 3 persons to put it on the wall.

Based on reviews, my flow sensors are definitely faulty, but it still doesn't explain the sudden new flow cut by half when i refilled the loop.
I can see the difference in my reservoirs. I don't think stuck bubbles could cut by half the flow as they don't go through the pump.

I guess i'll keep it as it is and hope that daily on/off will help a bit to move the stuck bubbles.

Thank you all for your advices on my issue! ;)