GHL Maxi - RO tubing mod

[AZMSGT]

I had my Maxi up and running with RO tubing as the in and out tubing. However I had one line pop off on me and I have not trusted the set up.

I saw a few pictures where APEX owners modified their DOS. Since the pump heads are practically identical I thought I would modify my MAXI pumps.

You need to cut the end off or it will get in the way of the tubing when the RO tube is installed in the new fittings.

You need to use a sealant on the threads before installing the fittings.

These are the fittings I installed. I only tightened them by hand. Using a wrench or anything else I was worried about breaking something. Got them on Amazon

I installed locking clips to ensure no slipping of the RO lines.

Here’s the finished pumps.

 

[Ditto]

Nice tip!! How it working?

 

[AZMSGT]

Nice tip!! How it working?

So far so good, just finished it about 3 hours ago. Ran 1000ml through each pump for leak checks.

 

[Kyl]

It will be 100%, the fittings don't leak unless they're physically damaged.

 

[esther]

I had my Maxi up and running with RO tubing as the in and out tubing. However I had one line pop off on me and I have not trusted the set up.

I saw a few pictures where APEX owners modified their DOS. Since the pump heads are practically identical I thought I would modify my MAXI pumps.

You need to cut the end off or it will get in the way of the tubing when the RO tube is installed in the new fittings.

You need to use a sealant on the threads before installing the fittings.

These are the fittings I installed. Got them on Amazon

I installed locking clips to ensure no slipping of the RO lines.

Here’s the finished pumps.

Looks good!

 

[Vinny@GHLUSA Verified Sponsor]

Nice find.
Thanks for sharing!

 

[Macca_75]

JG fittings out of the factory would be great - they are pretty common if not the industry standard in reefing.

 

[AZMSGT]

JG fittings out of the factory would be great - they are pretty common if not the industry standard in reefing.

Nice thing is it’s an easy mod.

 

[jsker]

I had my Maxi up and running with RO tubing as the in and out tubing. However I had one line pop off on me and I have not trusted the set up.

I saw a few pictures where APEX owners modified their DOS. Since the pump heads are practically identical I thought I would modify my MAXI pumps.

You need to cut the end off or it will get in the way of the tubing when the RO tube is installed in the new fittings.

You need to use a sealant on the threads before installing the fittings.

These are the fittings I installed. I only tightened them by hand. Using a wrench or anything else I was worried about breaking something. Got them on Amazon

I installed locking clips to ensure no slipping of the RO lines.

Here’s the finished pumps.

That is brilliant, using the put locks. I am using silicone tubing instead of the water line tubing. The silicone is seating better without have to over stress the connections to the head.

I am print out the P-touch labels now.

 

[Tubbybeef]

JG fittings out of the factory would be great - they are pretty common if not the industry standard in reefing.

Just closing the loop for anyone considering a GHL Doser Maxi 2.2... they seem to now ship with push connect 1/4" poly line connectors (John Guest) pre-installed.

When my Maxi arrived, the package also included a pack of four free barb adapters (one shown in the image installed on the right hand connection). If someone wanted to run with barbed connections they still could.

Nice to see GHL listening.

 

[Cali9dub]

Those barb adapters are 6mm to 1/4” ? Or 6mm to 6mm ?

 

[Tubbybeef]

The adapters are male 1/4" (smooth like RO tubing) to male 6mm barb. I can either push 1/4" RO tubing into the pump or I can push these black adapters into the pump and then slip 6mm tubing onto the adapters.

 

[Cali9dub]

Hmmmm. Those don’t leak? The John guest on the pump are 6mm. If those blue rings were black they’d be 1/4”. If you look on that blue ring of the connector you’ll see a 6 instead of 1/4

 

[Tubbybeef]

Hmmmm. Those don’t leak? The John guest on the pump are 6mm. If those blue rings were black they’d be 1/4”. If you look on that blue ring of the connector you’ll see a 6 instead of 1/4

Oof, thank you, you are right. The fittings are not 1/4" they are 6mm (I found the "6" mark on the blue ring which you suggested I look for).

I think I could just about jam RO tubing in there but it is juuuuuust off enough that I wouldn't want to risk it.

I knew it was too straight forward to be true, lol.

 

[Cali9dub]

They do sell John guest fittings that are 6mm on one end and 1/4 on the other. Check Amazon. And remember the blue side is 6 and the black side will be 1/4”

 

[Matthias Gross Verified Sponsor]

the Doser 2.2 Maxi push-fittings are for 6mm (not 1/4", which is 6.35mm) semi-rigid tubing or our barb adapters, which are included

 

[chema]

I'm finding it very difficult to pull out the tubes once inserted into the fittings. That has happened either for the GHL black barb adapters and for RO tubing. Actually the whole internal fitting (the small ring pieces inside the black piece) came out when I tried to pull out one of the RO tubes.

I have been using JG adapters for my water purification system for a long time and I never found this kind of problem.

Is someone experiencing this?

 

[Matthias Gross Verified Sponsor]

As far as I can see JG has mostly imperial sizes, but I don't know what you use.
If you use 6mm tubes and not 1/4" (= 6.35mm) then you should have no problems.

 

[chema]

As far as I can see JG has mostly imperial sizes, but I don't know what you use.
If you use 6mm tubes and not 1/4" (= 6.35mm) then you should have no problems.

Thank you, but I'm having that problem even with the GHL barb adapters.

However, in the case of the mentioned fitting, Is there a way to to put it back inside the black piece? If not, is there a replacement spare part?

 

[Matthias Gross Verified Sponsor]

You can put some lubricant on the end of the tube or the adapter to improve sliding.
Ideally use our dedicated peristaltic pump lubricant. Or if nothing else at hand Vaseline.
Of course there are replacement tubes available in the shop which come with 2 new fittings.