you can use other coolants, but the resistivity sensor is specifically calibrated for DP Ultra. So by using other coolants, you may have resistivity values that are irrelevant.
But if you only care about the temperature and flow sensors, it doesn't matter

The High Flow Next conductivity sensor can measure from 2 to 200uS/cm. DP Ultra starts out with very low conductivity - around 10uS/cm. The conductivity rises over time. Aquacomputer recommends replacing the coolant when conductivity gets to 100uS/cm. I don't know how much the conductivity varies among the various brands of coolant, but there was a very interesting thread on this forum about EK Cryofuel. The Cryofuel product page states that the coolant has Low electrical conductivity, but in the specs it says its 1.04mS/cm +/-10%. 1.04mS/cm is 1040uS/cm. That is over 5X higher than the maximum conductivity the sensor in the High Flow Next can measure. The OP in the thread contacted EK and was told that Cryofiuel's conductivity is actually even higher - on average 2330uS/cm. This is over 11X higher than the sensor's maximum. Here is a LINK to the post where EK is quoted saying this. The walk away was that EK and Aquacomputer have very different opinions on what "Low Electrical Conductivity" is, and the conductivity sensor in the High Flow Next will not work properly with EK Cryofuel.

One other thing to consider is that the flow sensor in the High Flow Next can be calibrated for DP Ultra or Distilled Water. I have changed this setting back and forth between the 2 settings. Changing the setting from DP Ultra to Distilled increases the flow rate by 8l/hr, at least when the flow rate is in the neighborhood of 225l/hr. I don't know if the offset is linear across the flow rate range. I think this compensates for the viscosity of DP Ultra. If you use a different brand, the flow rate accuracy may be off. You can manually calibrate the reading. It even has a multi-point curve similar to a fan speed curve. That's nice to have but I don't know how you would know what to set the calibration offsets to.

Flow Rate is affected by viscosity and density (which is affected by temperature). Different coolants will likely have different viscosities and densities than DP Ultra or distilled water. This may affect the accuracy of the flow sensor. The High Flow models are very accurate flow meters - better than most if not all on the market for this purpose. They are not "lab grade" flow meters but THIS REVIEW by Igor's lab shows how accurate the High Flow sensor is (and how inaccurate some others are). I have 2 of them in my test loop that read within 1.1% of each other. To get the most out of this device, it make sense to use the coolant it has been optimized for.

Coolants that use the "additive" style EK does (you often can purchase them as concentrates) will read too high.
Coolants based on glycol like DP ultra (that you usually can't find as concentrates) will read low and may work with the High flow next basically.

To know which is which, you'll have to look at the MSDS of the coolant you want to use. it may give you a clue as to what you can expect. DP ultra from the datasheet is 20-35% ethylene glycol and less than 1% of anticorrosion additive.
Cryofuel uses another anticorrosive that renders the water more conductive, plus a biocide, but it's less viscous than a glycol mixture (all things relative.. it's not honey thick :p the tiny correction factor on the HFN shows how small the difference is) and glycol lowers the heat capacity of the coolant somewhat (but it doesn't matter one bit for PC watercooling either. It's only useful to know when calculating the dissipated power, for watercooling nerds).

Both options are perfectly fine. the EK approach is closer to the old DIY coolant where people use DI water and add a few drops of biocide and anticorrosive. AC looks closer to the AIO approach of using a glycol mix.

Soooo yep. if you care about the conductivity sensor, by all means go DP ultra. Using any other coolant, you won't be able to tell when it needs to be changed, since... there's no saying what acceptable values are.

... and on a personal note.. those additives used in cryofuel and other similar coolants are pretty nasty. I still use Cryofuel personally, but i have had some pretty severe skin rashes when accidentally exposed to it. These definitely require gloves when doing a coolant change. Glycol based coolant are a lot safer to be honest.

See? you ask a simple question and we go above and beyond to complicate the answers lol

How is Mayhems XT-1 Nuke with the High Flow Next? Below is a link to the datasheet, but I can't find the information about the conductivity value. Perhaps one of you can glean/decipher this information from the datasheet. I just don't see it.http://assets.watercool.de/pdf/Xt1.pdf

they don't list all those physical characteristics, only the constituents.
Here it's <90% ethylene glycol and <8% DI water. the missing % is their secret sauce so there's no saying what it does to conductivity already.

Oddly enough they sell that one as a concentrate but the end product is a glycol mixture like the DP ultra. And as for the conductivity, it will be highly variable because it will mostly depend on the quality of the water you will dilute it into, how much water you use (yes, they don't specify any water/ concentrate ratio), and those mysterious additives they do not list in the MSDS.

Zitat von »Remayz«

they don't list all those physical characteristics, only the constituents.
Here it's <90% ethylene glycol and <8% DI water. the missing % is their secret sauce so there's no saying what it does to conductivity already.

Oddly enough they sell that one as a concentrate but the end product is a glycol mixture like the DP ultra. And as for the conductivity, it will be highly variable because it will mostly depend on the quality of the water you will dilute it into, how much water you use (yes, they don't specify any water/ concentrate ratio), and those mysterious additives they do not list in the MSDS.

Thanks. So, they don't list the information for this product. I guess they consider it proprietary or something. Just an FYI. They do provide the various mixture ratio (10%-60%) for the concentrate on their website and in their manual. You can make it as strong or weak as needed.

Well the MSDS is purely a product safety information sheet. it never gives any technical data that's not relevant to safety. It's just a good way to have an idea of what's in the bottle, but it's not a recipe or a technical datasheet yep.

it's going to be similar to the cryofuel clear anyway. If you don't use DP ultra, just ignore the conductivity sensor. You should change the coolant at least once a year anyway.

Zitat von »funnelweb«

Zitat von »Remayz«

Thanks for the detailed answer ,I contacted ek and asked for the conductivity of the mystic fog and was told the conductivity of coolants is not available to the public!!

I could not find a post from Remayz where he said that he contacted EK and was told the conductivity of their coolants is not available to the public. Either the quote is messed up, the post was deleted or altered, the forum search functions have issues, or I am blind.

Whatever the case, we have someone stating that EK told them they do not provide conductivity for their coolants, while the WEB PAGE for Cryofuel clearly states that the conductivity is 1.04mS/cm (+/-10%). Curiously, the Mystic Fog web page just says "low electrical conductivity" but does not list a value. When the OP of the original discussion asked EK about this, he claimed they said that Cryofuel conductivity is 2.33mS/cm which is over double what their own spec says. So we have a spec that says 1.04mS/cm, a second hand verbal statement that its 2.33mS/cm, and another statement that this information is not available to the public. Kind of makes me wonder what is going on at EK.

I will just stick with DP Ultra so I can use the conductivity sensor in my High Flow Next and not have to worry about what Aquacomputer considers to be extremely highly conductive fluid circulating in my loop, or having to wear gloves when handling coolant so my skin does not slough off! I cannot think of a single advantage to using Cryofuel. Am I missing something?

From the Cryofuel web page:
Cryofuel Characteristics & Specs C.jpg

it has more water than DP ultra?

They all perform the same anyway. The only advantage of DP ultra could also be that it's the only one that works with the High flow Next sensor.. calibrated just for it.
But since you should replace your coolant yearly regardless of the reading (also stated in the DP ultra page), it's kind of irrelevant. The conductivity reading is a nice thing to have but its real use is limited since past 12 months, the manufacturer recommends that you change it anyway.

And yes, the quote is messed up, i didn't contact EK lol

Zitat von »funnelweb«

is it true i need to use only dp ultra with the next high flow next ?

or is it ok to use with other coolants out there?

According to the description of the high flow NEXT page, the water quality is determined by the conductivity, and the unit is us/cm. The higher the conductivity of the cooling medium, the poorer its quality. Fresh DP Ultra has a conductivity as high as 45 us/cm. The conductivity of tap water is 200-400 us/cm.
I have used the system for nearly two years after I built it, and the current conductivity is nearly 10 us/cm. I have not replaced the DP Ultra, and the performance is still good.

Not sure if it's any help, but I'm using Corsair XL8 (Clear) in my loop. Had it running for the last 6 months or so, and the High Flow Next reads the Conductivity currently as 32.9 uS/cm.

Zitat von »Caldorian«

Not sure if it's any help, but I'm using Corsair XL8 (Clear) in my loop. Had it running for the last 6 months or so, and the High Flow Next reads the Conductivity currently as 32.9 uS/cm.

I suspect that like most if not all of Corsair's cooling loop products, they are just rebranding coolant made by another company. A quick Google search for an MSDS sheet returned the attached. The MSDS sheet says their coolant is ultra-pure water with <20% 1,2-Propanediol which is Propylene Glycol. It also contains <1% of an unspecified Germicide Since it is Glycol based, it is not surprising that it has a conductivity similar to DP Ultra which uses Ethylene Glycol. Propylene Glycol is less toxic, but it also has a higher viscosity which lowers heat transfer efficiency. Since the conductivity of XL8 is within the range of the conductivity sensor in the High Flow Next, the conductivity sensor should work OK. Since PG has a higher viscosity, the flow rate accuracy may be affected. Your pump will also have to work a little harder to push the fluid through the loop.