Absolutely you can mix and match 1st / 2nd stages as long as you set the intermediate pressure to what the 2nd stage wants.
That said if you already have a set you can just get it swapped over from yoke > DIN.
https://www.amazon.com/Scubapro-Din-Conversion-Kit-Universal/dp/B0000DYVG3
I had the same issue. You may need to clean the drive screw and re-lube it. Mine works like new after this.
I used isopropyl on cotton balls and swabs to clean it. I used food grade silicon grease to re-lube. https://www.amazon.com/gp/product/B00CI88AZ4/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&th=1
I've since learned that the material is "compressed EVA". Using that search term helps.
Here's something, but the Halcyon & Shearwater zippers look better:
https://www.amazon.com/Hiturbo-Regulator-Density-Padded-Protective/dp/B08XVNXQVS
The bubbles only coming out of one return is likely that all the air is coming out there. Bubbles in pump basket I dealt with recently as well. I have an inground pool but to fix it I disconnected the pipe to the pool (mine has a screw on cap) and I took the two plugs out that mine has. They will normally be located at the bottom of where the basket is because they hold water in. Depending on size maybe there’s only one plug. And I took the basket lid off itself. I used the lubricant on All the fittings. This is the kind of thing you’re looking for - Haynes Silicone Grease, Food... https://www.amazon.com/dp/B00CI88AZ4?ref=ppx_pop_mob_ap_share. Just rub a little bit on that on any o rings and threading. Then put it all back very tight. For my fitting for the pump I used a tool to get it pretty tight obviously being careful since it’s also been asked to overdo with a tool like grippers. This fixed my issue. Bubbles from jets are always suction side of pump
Sounds like you just need a reducer, correct? I would think any pool store worth their salt should have something for you. Do you need something like this?
That's actually my normal configuration. I consider the Air2 as a second tier backup... for use in the super unlikely event that my primary second stage fails after the alternate has been handed off to a buddy, and we're not yet at the surface. It's almost certainly overkill, but I'm OK with that.
If you do decide to keep the Air2, however, you may want to pick up one of these inflator adapters. It lets you connect the Air2 hose to a standard BC inflator, should you ever have BC issues on a trip and need to rent a replacement. Basically just saves you from needing to take/purchase the additional hose.
The body of the DIN and yoke first stages are essentially the same. The only difference being section that attaches to the tank. For what you are wanting to do it is probably easier to buy a yoke first stage and then get the corresponding DIN conversion kit. That way you will have all the parts for both.
For some reason the manufacturers seem to expect you to switch from yoke to DIN and not the other way so there only seem to be DIN kits. Just make sure there is a kit available for the first stage you choose.
It is a pretty straight forward swap out with some basic tools but if you aren't comfortable doing it yourself any LDS that does servicing should be able to help.
Example:
I tried a seacure and a few others before I found the comfo-bite ones and they are awesome. Personally I like the feel of the Trident knock off more than the Apeks one but wouldn't hesitate to use either if I needed to swap one out.
https://www.amazon.com/Trident-Comfort-Mouth-Bridge-Rolled/dp/B00CD6IGJG/
I've found this style of mouthpiece makes a big difference:
But I still have to maintain awareness because I tend to clench when cold or nervous.
Awesome. I dont think I have one of those laying around unfortunately and this project is already overbudget, it would be good for an upgrade.
It would be a bit uncomfortably using hard material for the nose part though if you print a mold and then make it out of silicone it would work. Also what do you think of using a scuba diving mouthpiece instead?
I have a hardhat lying around somewhere at home, I should be able to take out the head holding part and paste it/clamp it.