Experience GHL maxi doser - leakage and flow!

[Dimorb]

Hi.

I have a GHL maxi 2 pumps that I use to feed water to my nitrate filters.

On New Year's Eve, the hose in pump 1 broke.

Had to search for a long time to find a replacement hose but finally found a hose in an old IKS pump that fit in relation to length and diameter. It is not exactly the same as GHL's own (slightly shorter and larger inside diameter)

The thing is that when I switch it on and have to calibrate the pump again, I get large differences in the amount of water.

When the pump, what new, gave the calibration a max of 298 ml / min - GHL's specifications say maximum capacity 320 ml / min - when I measure with the new hose I get 466 ml / min. Anyone else who has had the same experience or has thoughts about why there is such a big difference?

It is certainly not good for the pump to be pressed so hard but I have to run this until I get a new hose according to GHL's original - does anyone know the exact diameter / inside diameter of the hose?

Sees on the website that it should be 145 mm +/- 1 mm in length but sees nothing about how big the diameter is.

In short ... want to get experience - more who have received leakage from the hoses? How often is it recommended to change the hose? How wide should the strips be that hold the hoses in place etc..

Thanks in advance.

/Andre.

 

[Ron Reefman]

BUMP

Any help for Andre?

 

[elysics]

Its important to get the right size, if you have a larger inner diameter, the rollers might not compress the tube all the way. That might lead to the line emptying or siphoning on you. Did you throw away the old one already?

Bpt tubing is usually listed as lasting thousands of hours of use. Which is in the realm of months, not years, if you go continuous duty.

 

[ca1ore]

Heads appear to be the same as those on the DOS .... just blue instead of orange. I bought replacement pharmed peri tubing for my DOS from us plastic.

1/8" ID x 1/4" OD x 1/16" Wall Natural Food-Grade TPV 70A FDA Tubing | U.S. Plastic Corp.

TPV tubing, also known as thermoplastic rubber tubing, offers good mechanical properties under a wide range of operating temperatures.

www.usplastic.com

You want to replace the tubing in both heads at the same time.

Are you running it continuously? I considered one but could not find whether it’s rated for continuous duty .... though that is implied in the description. I replace the pharmed tubing on my MasterFlex every 3 months as it runs 24/7. Pumps that run occasionally, every year.

 

[elysics]

Heads appear to be the same as those on the DOS .... just blue instead of orange. I bought replacement pharmed peri tubing for my DOS from us plastic.

1/8" ID x 1/4" OD x 1/16" Wall Natural Food-Grade TPV 70A FDA Tubing | U.S. Plastic Corp.

TPV tubing, also known as thermoplastic rubber tubing, offers good mechanical properties under a wide range of operating temperatures.

www.usplastic.com

You want to replace the tubing in both heads at the same time.

Are you running it continuously? I considered one but could not find whether it’s rated for continuous duty .... though that is implied in the description. I replace the pharmed tubing on my MasterFlex every 3 months as it runs 24/7. Pumps that run occasionally, every year.

Just because the heads look exactly the same doesn't mean that the tubing is the same. The same type of head is usually produced with a whole array of tube sizing to choose from. In this case these are (very very likely) Honlite dosing heads or clones thereof, which exist with a wide array of tubing sizes, which they sadly don't list the specifications of on their sales pages as far as i can see. And GHL doesn't either. So your best bet would be to measure your original one if you still have it.

 

[ca1ore]

Of course not .... thus my use of the word 'appears'. However, in this case the internals appear to be the same as well, including the rollers. Easy enough to pop off the shell and measure the tubing. It is less important to match the ID exactly as it is to use the same tubing on both heads. Replacement tubing I have used on the DOS head has the same OD but has a slightly smaller ID. Calibration fixes that. Not really rocket science.

 

[AZMSGT]

Just because the heads look exactly the same doesn't mean that the tubing is the same. The same type of head is usually produced with a whole array of tube sizing to choose from. In this case these are (very very likely) Honlite dosing heads or clones thereof, which exist with a wide array of tubing sizes, which they sadly don't list the specifications of on their sales pages as far as i can see. And GHL doesn't either. So your best bet would be to measure your original one if you still have it.

The Neptune DOS head and GHL head are made at the same place they use the same tubing. The only difference between them is that DOS uses a 2 roller setting and GHL uses a 3 roller setting. This has been discussed in the GHL forum several times.

Many people in the GHL community have used DOS parts. They cost allot less and the shipping from most dealers of Neptune DOS is much cheaper than GHL.

If a person uses the Apex roller or tubing on the GHL all they have to do is a recalibration and all is good.

 

[lakai]

https://www.mcmaster.com/52035K48 this is what I replaced the tubing with. It's Tygon-A60-F 5mm ID and 7mm OD, NSF and 60 Durometer and best off all it is cheap. If you need a replacement head you can get one here https://www.aliexpress.com/item/4000016660495.html?spm=a2g0o.cart.0.0.44963c00AbeC3E&mp=1 Honlite is the OEM. The only thing is while the head with tubing is $11 , the shipping is $31. In most cases you will only needto replace the tubing.