Serious defect with GHL dosers

cmw · Apr 28, 2019

I have a two GHL dosers (2.1 master/slave) that are less than a year old and in the last 6 months I have had 3 heads break. All in the exact same way. The guide plastic on the outer shell breaks and jams in the head. Two times on the ALK head which dropped my ALK from 8.5 to 6 and this most recent time on my calcium head. I love the GHL dosers but this is a huge issue for me. I have a LOT of coral and I can’t risk using something that is going to break again and again. It seems to only happen on the heads that get the most use. Anyone else experience this?

ispookie666 · Apr 28, 2019

Too many threads which have highlighted this issue. I have replaced two heads with the newer ones which are of different quality.

WWIII · Apr 28, 2019

Yes I've had this issue on the dosing heads when they are set to speed 3. I have my actual dosing heads (calcium/alkalinity) on the slowest speed "0" which never have had a problem in almost 2 years. On the other heads, where I've had problems, the dosers were set to speed 3. I've gone through quite a few. There are however new caps that seem to be much better. They have been out for several months, maybe a bit longer. Anyways, the new material blue caps have a small dot melted into the bottom right corner of the cap. That is how to tell if it's the new material. I'd say it's a good possibility all the "old" caps are now gone from inventory and would expect to get these new caps if I ordered them today.

Here you can see the small dot on the bottom right, indicating the new material caps...

Ditto · Apr 29, 2019

@WWIII - I have to agree with him. I have gone through a few of the old style heads on the pumps running at speed 3. After the new cap is placed on they been pretty good.

One thing I have noticed specifically on one doser head only I get black streaks in the middle of the roller constantly, which requires me to clean it ever 2-3 months.

Contact support about your doser head issue they are great and should be covered under warranty.

WWIII · Apr 29, 2019

Oh another thing I have done occasionally is if I hear or see any dosing head rubbing or making noise. I take it apart, clean the blue cap and rollers with an alcohol wipe, then apply a tiny amount of lubricant to the blue cap. I think I use a food grade silicone lubricant. I place a small dot on the inside of the cap, spread it around the whole cap and clean off any excess. Don't put too much and only on the blue cap. This makes the heads completely silent again and no rubbing.

Again this is only on my speed 3 heads and I haven't had any issues yet with the new blue caps shown above.

Vinny@GHLUSA · Apr 30, 2019

@cmw
This is something that has long been addressed.
Please open a support ticket so we may assist.
https://www.aquariumcomputer.com/support/tickets-enquiries/