Once again you can get these dozens of places for next to nothing and in short period of time you can have a tough reliable regulator and have some fun putting it together.
You need only normal hand tools and an intermediate pressure gauge. SAFETY NOTE HERE....Anytime you are working on a 1st stage you should have a pressure relief device on it in the event the intermediate pressure swings out of control. This can be as simple as a second stage attached to it or for the tool junkie get an intermediate pressure gauge with a built in over pressure relief.
LINK TO AQUARIUS SERVICE INFORMATION FILES
The Aquarius first stage is a one piece unit made from a solid chunk of chrome plated brass. It has 2 low pressure ports and one high pressure ports.....Note. It's a vintage regulator so all ports are 3/8" thread. Don't put a low pressure hose on the high pressure port or your hose will go BOOM. The high pressure port has HP stamped by it.
Service is very straightforward with the high pressure seat being the only challenging area for those not accustomed to it. The seat is an interference fit and fits TIGHT. Two ways to remove it that have worked for me are....Shoot a blast of air in the base of the piston and often the seat will fly out of the end...Safety Glasses Anyone? Or a bit more controlled is to carefully push a very small straight pick up in the piston and push the seat out from the backside.
The Aquarius came like all other USD regulators of the era with the 1085 second stage.....10' tall and bullet proof. Follow the instructions in the manual to service it.
Link to Aquarius Service Kit
Link to 1085 Second Stage Kit
Servicing and diving with regulators like this are great confidence builders for those wanting to service their own gear. They are certainly not the most glamorous or "Hi Tec" rigs around these days but like a fixed blade knife you can count on it when needed.
Pet Peeve 101......Shortcuts when servicing a regulator.....I'm well aware you can save the $9.00 cost of the Aquarius service kit by flipping over the seat and greasing up 40+ year old O rings and most likely get it to work just fine..BUT WHY DO IT? I guess if you see it as a "challenge" that's one thing but if you are planning on going diving with it why would any person with even a tiny bit of common sense not spend the coin and insure everything is up to snuff?
"I've been diving with my XXXX for 30 years and never serviced it and surprise surprise surprise it crapped out on me in the middle of a dive"
When you are this stupid it's not a question of IF it will fail, only WHEN it will fail.....Please do it on your own time and don't ruin a dive trip for the rest of us when you become a statistic.....You don't impress anyone but yourself. Best case scenario you end up looking like a fool....Worst case you end up dead.
Start your Aquarius search now :)
Have fun and be safe....If you don't know ASK.