The lowest temp you have taken your MK25 to.

[elan]

I had an opportunity to get a set of MK25 (only 1st stages) to use on the doubles. I got them mostly for the reason of good routing on doubles and of cause the rule #6 played a major part :)

So I have a question for those who dive them in the lower temperatures, especially folks diving in the lakes.

What was the lowest temperature you have been taking them routinely without free flowing. I witnessed people diving them as low as 39F.

I have an Apeks ATX50 and Zeagle ZX laying on a shelf that I'm planning to use on them. And those are good cold water second stages which I'm very confident in.

I also have a set of Flathead VIs and my wife has a set of Apeks TEK3 which I can dive in Dec-Feb in the icy water with sub 32F surface temps.

The tanks I will be using them with are mostly LP (184 bar) and Alu (206bar).

Another question would be how often do you overhaul them (not because it is required by the dealer to maintain the warranty but because they need it)

Any feedback regarding their performance in cold water would be appreciated :) Thanks.

[TSandM]

I've had mine for about five years. I routinely dive them in 45 degree water, and have had them down to 41. No problems. They are supposed to get serviced every year, but given that I haven't had a good system for keeping track of which of our 19 regulators needs service, it's been averaging more like every two years.

[craracer]

I've had mine down to 41°F without a problem. However, I've had several people tell me that they know people who've had free-flow problems. Personally I do not know of anyone who has, so I consider this to be anecdotal. Nevertheless, I've relegated my MK25/S600's to stage bottles.

I also have the Flathead VI's, and have not had an issue with free-flow in cold temps. I use them as my primary and secondary on LP100 twins.

I service all of my regs yearly. I use my iPod to keep track of when the serice dates are due.

**EDIT: Fresh water dives

[Peter_C]

I had mine down under a thermocline where my gauge read 37 degrees, diving in Fallen Leaf Lake. It was nice and refreshing after the much higher water temps in the shallows.

[gcarter]

I had mine down under a thermocline where my gauge read 37 degrees, diving in Fallen Leaf Lake. It was nice and refreshing after the much higher water temps in the shallows.

Apparently the world is full of whack jobs.

:D Just joking :D

[bleeb]

Also, please specify whether those temperatures are in salt or fresh water. (I'll take the people who have mentioned lakes to be in fresh water. :))

[tstormdiver]

I have only had 1 free flow of mine. It was kind of a fluke during my Adv. Nitrox/ Deco class (during a valve shutdown drill I tapped the purge of the second stage). The waters I frequently dive is a freshwater quarry & the bottom temps are 40- 43 degrees.

[IanBrit]

I frequently take mine (mk25+s600) into sub 40F water without issues including below the ice. However, one of my buddies with a similar setup (differences in the model of the S600) has constant free flow issues in the same water.

[elan]

Thanks everyone. It looks like they should be good for the most part of my diving

Good point about fresh/salt Im doing mostly fresh water.

[beaverdivers]

I have taken my MK 25/S 600 in lakes down to 37 degrees. No problems.

[ajduplessis]

40 was the max for me. No problems thou

[Pullmyfinger]

44 for me, in salt water. I experienced no problems.

-Mitch

[CPH]

I dive under ice with no problems.
My friend in Norway dives under ice alot and in the cold fjords.
The secret is not to breath BEFORE you get the regs under the water. Most of the time, the water is warmer than the air, so breathing in the air will cause them to get very cold. The temp of the water helps to stop them freezing.

[Pedro Burrito]

I'm had my Mk25 down to 42° F in fresh water a few times. My Scubapro tech told me to never take a Mk25 below 52° F. Then he tried to sell me a Mk17. ;)

[elan]

I'm had my Mk25 down to 42° F in fresh water a few times. My Scubapro tech told me to never take a Mk25 below 52° F. Then he tried to sell me a Mk17. ;)

Haha I guess 52 comes from roughly 10C which they consider a cold water.

I see folks diving 25th here in 40f range paired with a good cold water second like g250 or an apeks which made me getting them with no hesitation. Some dive tthem even with the older S600 with a plastic barrel but I have seen S600 freeflowing in that water on mk17

[elan]

I dive under ice with no problems.
My friend in Norway dives under ice alot and in the cold fjords.
The secret is not to breath BEFORE you get the regs under the water. Most of the time, the water is warmer than the air, so breathing in the air will cause them to get very cold. The temp of the water helps to stop them freezing.

CPH you are right we never breath the regs until we hit the water. Even Apekses or any enviro sealed reg.
If in the shallows we submerge the 1st stages as well as the seconds for sometime to let them heat up and then go down. Or just drop a stage before the dive and start breathing from it as it would be warm by that moment.
We then do a bubble check and might switch to the back gas.
In winter sometimes we dive at -10 c temp while the water is +2


I have seen Apekses and poseidons flowing simply because the divers were testing the reg at -10

[Graeme Tolton]

Nothing is foolproof. :) even the best regs will freeflow if not set up properly. For my cold water apeks, i have the ip turned down to 130 psi. I have only ever had 1 freeflow on them and that was a result of inflating a lift bag at 140' in 37 degree water to recover a mooring line at a wreck site. Scary part was having the secondary freeflow at the same time. I kept cool and got everything under control. That being said, i lost 1000 psi in a matter of about 10 seconds.

I did also have with me a stage of air, but managed to not need it.

Having not only the proper regs, but proper tuning is absolutely necessary.

[elan]

I have them set at about 130-135 (hard to say exactly with the gauge I have)

What happen to you sounds like there was a bit of moisture either in the regs or tanks.
I had the same happen to me on the Ceder once. I think the regs were not dry and a bit of moisture got into the regs. 2 out of 3 flowed

[Graeme Tolton]

That is entirely possible. Could have even been a slightly wet fill. Too bad compressors cant always be run in cold weather.

[halocline]

I'm not sure the lower IP actually does anything, especially with high performance 1sts, and balanced 2nd stages. The idea is that lower IP=less flow to the 2nd stage, and to a certain extent less adiabatic cooling at the 2nd stage, because IP is closer to ambient. But, the lower IP also results in a bigger drop at the 1st stage, which means at least theoretically more adiabatic cooling at the 1st stage, so with a MK25, that point might be your most free-flow prone. This is all speculation on my part....but I suspect the old school practice of lowering IP for increased freeze resistance is more effective with lower performance 1sts and/or unbalanced 2nds, where the 2nd stage does really slow down the flow when presented with lower IP.

Certainly full purges are likely to have a bit more flow at 145PSI than 125PSI.

[nielsent]

I personally don't own any scubapro regs, but I do know a commercial diver here who brings his regs to the shop for servicing, he states that the Mk25's don't really cause free flow issues until you are working really hard in below 32F water. Recently he brought them in for service and attested that he had an uncontrollable freeflow while working in 25F water, The scenario was heavy work (commercial urchin harvesting) while using a mk25 & G250V on a Full face mask.

I would personally be going with a mk17 in these waters, but it certainly attests to the capabilities of the Mk25.

HTH

Travis

[diveredon]

I have had them to 38f. I get them serviced annually. Partly because of warranty, mostlyl because they are used often. They are married to s600 second stages. I have had no issues with free flow. I don't do any extremely strenuous diving/ work while in cold water. I like ships and sight seeing. Many of my friends use the same set up with no issues.

[jbomb001]

i use a mk 25 g 250 v and have had no issues in 33F in lake ontario. set breathes great and have yet to have a free flow issue

[Tarmin]

I have a combo of MK25 and MK17 with S600 on my twins (independant) that I use in the Great Lake year round and never had a problem. I've also been using a Mares Abyss on single tank for 17 years and works very well for Ice or Maritimes diving ! I wonder if there's any colder water then Halifax ??? Lol

[Skookumchuck]

I did a short dive in the Fraser river last January with mine and had no problems in 34 degree water.