PEX for mouning frags. Will it leach?

JCOLE

Grower of the Small Polyps
View Badges
Joined
Mar 12, 2018
Messages
4,078
Reaction score
11,016
Location
Charlotte, NC
Rating - 0%
0   0   0
Hello everyone!

I mentioned this in my build thread but wanted to post here as well to get more eyes on it.

I have been wanting to come up with something for frag mounting on my rocks for awhile now due to limited space and I am finally going to work on it this weekend. I have limited rock space and will need to bump out my new corals for growth and looks.

The idea is to use PEX tubing and mount it to the rocks. The frags slide in with almost a perfect fit. I am thinking it would allow me to move frags around without mounting permanently if needed. They had red, white, or blue. I figured red would look best until covered in coralline algae. I am going to have small ones and also use my heat gun to angle some so I can mount some away from the rocks.

What do you all think and does anyone know if PEX will leach anything overtime?

20211126_194703.jpg
20211126_194713.jpg
 

DrZoidburg

Valuable Member
View Badges
Joined
May 22, 2021
Messages
1,588
Reaction score
1,083
Location
Near Lake George
Rating - 0%
0   0   0
I believe it is a type of hdpe so generally should be safe. I believe it does break down under UV though.
Yes under light exposure but there are other things like chlorine, and other negative charged thing that will break the crosslinks in hdpe chemical structure. If it is in there long enough. This is why it is resistant, it only resists chemical attack. Will it leach nasties out definitely.
 
OP
OP
JCOLE

JCOLE

Grower of the Small Polyps
View Badges
Joined
Mar 12, 2018
Messages
4,078
Reaction score
11,016
Location
Charlotte, NC
Rating - 0%
0   0   0
Thank you for the links. I have the Sharkbite PEX 5306 and it appears to be PEX-B and the best out of the bunch.

Approved for use in potable water installations.
Has the highest Chlorine Resistance Rating (Level 5 for Continuous Recirculation Systems).
Has the highest UV Resistance Rating (Level 3 for 6-month UV Resistance).

PEX-B is a clear winner in terms of price vs. both other types. It has been in use for over 40 years with no known issues.


What I like is that it mentions no known issues and I do not see where it mentions leaching like PEX-A does.
 

DrZoidburg

Valuable Member
View Badges
Joined
May 22, 2021
Messages
1,588
Reaction score
1,083
Location
Near Lake George
Rating - 0%
0   0   0
@JCOLE It will but in just water it will be lower rate. To give you a idea I store concentrated chemicals in hdpe. I get about 1 year on them +/-. before they start changing color or cracking.
 
OP
OP
JCOLE

JCOLE

Grower of the Small Polyps
View Badges
Joined
Mar 12, 2018
Messages
4,078
Reaction score
11,016
Location
Charlotte, NC
Rating - 0%
0   0   0
What about CPVC versus PEX? Seems stronger and same size.

20211127_125818_001.jpg
20211127_125839.jpg
 

DrZoidburg

Valuable Member
View Badges
Joined
May 22, 2021
Messages
1,588
Reaction score
1,083
Location
Near Lake George
Rating - 0%
0   0   0
What about CPVC versus PEX? Seems stronger and same size.
This can too, but again pretty resistant. The heat gun idea though I would be careful of. Going too high could cause it to leach more. I.e heat degrading the polymer a little. Even just heating it releases some. Good to not go much higher in temp than the point it will bend at, and don't breath in the fumes.
 
OP
OP
JCOLE

JCOLE

Grower of the Small Polyps
View Badges
Joined
Mar 12, 2018
Messages
4,078
Reaction score
11,016
Location
Charlotte, NC
Rating - 0%
0   0   0
This can too, but again pretty resistant. The heat gun idea though I would be careful of. Going too high could cause it to leach more. I.e heat degrading the polymer a little. Even just heating it releases some. Good to not go much higher in temp than the point it will bend at, and don't breath in the fumes.

Thank you. I have acrylic rod and might just use that instead. I just liked the PEX idea because it will allow temp placement instead of permanent.

20211127_132632.jpg
20211127_132636.jpg
 
OP
OP
JCOLE

JCOLE

Grower of the Small Polyps
View Badges
Joined
Mar 12, 2018
Messages
4,078
Reaction score
11,016
Location
Charlotte, NC
Rating - 0%
0   0   0
I'm more curious how he's going to attach them to the rocks? Theres not much surface area to glue/epoxy to.

I was going to either cross cut the bottoms and heat to flare out for extra surface area. Or just mount as is. Going to take putty and make a surface area large enough for the pipe to slide in and hopefully putty will go inside and I could form the putty around the bottom edges to the rocks. Sounds good at least. :)
 

homer1475

Figuring out the hobby one coral at a time.
View Badges
Joined
Apr 24, 2018
Messages
11,677
Reaction score
18,662
Location
Way upstate NY
Rating - 0%
0   0   0
I was going to plumb my mixing station with PEX, but then thought about the brass crimp rings. Even though they are on the outside, I didn't want to take any chances.

I replumed my entire house with pex. Great stuff, very easy to work with, and unlike copper, it doesn't split when the water inside freezes.
 

DrZoidburg

Valuable Member
View Badges
Joined
May 22, 2021
Messages
1,588
Reaction score
1,083
Location
Near Lake George
Rating - 0%
0   0   0
A lot of the problems need conditions to be problems.
Thank you. I have acrylic rod and might just use that instead. I just liked the PEX idea because it will allow temp placement instead of permanent.
Maybe a better option for long term. Less prone to leach under stress. More under uv, and in solvents. That is from what I read briefly but unidentified products. Assuming probably not as bad as the others. In the case of cpvc some of the test results in documents are from the solvents to glue joints, also some from plastic, and plastic that is heated. It is really low levels. Mostly sure none of these would be a problem for short times. When you add heat and salt water later that is different rates. Still maybe not bad but will things leach biproducts yes. Almost every plastic can do this. Anything that can cause a polymer, or impurities inside to degrade whether it is heat, uv, or chemical attack will cause leaching. Saltwater has numerous things that can do this. Maybe a pain to get frag to attach to rod though.
 

BCSreef

Well-Known Member
View Badges
Joined
Jan 22, 2016
Messages
599
Reaction score
482
Location
Maineville, OH
Rating - 0%
0   0   0
Since PEX has not been extensively used in marine systems, it may be best to avoid due to the unknowns. CPVC or PVC may be safer options. Although, they are known to leach some Sn. However, I have not seen any elevated Sn in ICP analyses after installing new PVC.

I would go with gray PVC since it will be less of an eye sore than white or bright colors. They also make PVC in clear ($$).
 
Back
Top