Quoted from "denny"

When the speed of my two D5 NEXT is about 2500 rpm,The negative pressure required by the system is 198mbar. When the speed is 3000 rpm, the system negative pressure demand is 238mbar.
Two D5 NEXT can also work but cannot exceed the limit of 450mbar. Normal operation without alarm

[/url]aquasuite_2021-10-25_00-19-57 by Jacob Tien, 於 Flickr[/img]

How hard is the Leakshield supposed to tighten to the Ultitube?
I find it difficult to find the right amount of "turn" to achieve a good seal.
I'm talking less than 1 degree.
I also find it difficult to figure out what my numbers should be.

I've just built a loop and have the same problem that a few others have mentioned.

The system is water tight, I can run the pump at 100% without leakshield protection and not a single drop leaks out. However, when I turn on leakshield I can see a small bubble getting sucked in every 5 seconds or so. The annoying bit is that it gets trapped in the cpu block. I've actually identified two places in my loop where bubbles appear and both of them had the 180 degree 5-way rotary adaptor - https://shop.aquacomputer.de/product_inf…roducts_id=4080

So it looks like this particular adaptor leaks air. I didn't want to redo the loop at the moment so I wrapped the fittings with teflon tape and that solved the air leaks. Not sure if there is a better material to seal the fitting but I had some teflon tape at hand it it helped. Some air still leaks in at 400+ negative pressure, but I run my pump at 2500 rpm and leakshield calculated that only 110 negative pressure is required for protection. The pressure stabilized for me at ~160 and at this level no air leaks in.

In the future I will avoid fittings that have 2 or more rotary parts.

Something like this should be better https://www.amazon.de/Scotch-4704-Repara…&language=en_GB
or this https://www.amazon.de/-/en/Poppstar-Self…ps%2C83&sr=8-38

I'm curious as to what the expected performance is.

1. I tested my loop as I built it with air, I was getting at most 1 mbar in 15 min with air this seemed to be OK.
2. I now have the loop filled with DI water for testing, it was sort of bad to start with, you really have to tighten the cap. I'm just in monitor mode.

It pump back to 56 mbar every 2-3 hours.

In another thread it was reported that 2-3 times a day for the pump to activate is OK and a great system would be once every 3 day.

My loop has D5 Ultitube 100, highflow next, 420 mm Rad and CPU block. I have pump at constant 3000 rpm

Quoted from "Ytterbium"

I'm curious as to what the expected performance is.

This is easy, look in the Aquasuite -> LEAKSHIELD -> LEAKSHIELD, there you will find the values for the pumping time in the lower diagram.
Normal <30 seconds per day
Alarming >30 seconds per day
Critical > 60 seconds per day

Set your LEAKSHIELD to Shield and see what happens.

To answer any questions about your system, we need much more information.

What information extra would you need?

looking at the chart it was 36 s for the day but I assume its a little higher in the 24 h leak test as you are degassing the coolant slowly, plus I had the cap not so tight at the start. in HWInfo the average leak rate over 24 h was -0.1 ml/h so it seems to be fine overall.

I filled my system with DP ultra and monitored for another 24 h, there was 38 s of pumping to establish the 433 mbar initially and there has been no further, so it seems a little less drop with this set up. Again 1st 24 h is probably more as there is degassing of the coolant, it looks to be on course for expected performance now. After about 90 hours it finally needed to pump, so the pressure leak rate was 0.04 mbar/h on average

my system is currently running like this, so i want to add a leakshield, would this work?