High Tide Aquatics

GHL KH Director vs KH Guardian

IOnceWasLegend

Frag Swap Coordinator
BOD
I'm getting sick of dosing tanks by hand, so I'm starting to look into alkalinity automation. I think I've settled more or less on the KH Director or the KH Guardian, but trying to figure out the major differences between them. Cost-wise, I think the two are roughly equivalent for me since I have a shiny new GHL doser, so I'm struggling to pick one.

If anybody has used both of them, I'd especially love to hear from you. And @ofzakaria , I know you've highly recommended the KH Guardian before, but also recall you recommending the director, and would love to hear your input if you have time. :)
 
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I have the KHG and it's working well for me. I was surprised by how much I've had to fiddle with and work on it over the last 9 months or so. I've replaced some split tubing and check valves and also pulled it apart a few times to trace issues. I've replaced the float valve as well but that wasn't actually the problem. Alex hooked me up with a new one gratis while troubleshooting. Customer service is excellent.

Within the next 3-4 months I'll probably replace the tubing for the pumps and start monitoring the ph probe a bit closer pending the 18 month recommended replacement.

Can't say anything about the KHD but that online comments from users make it out to be a bit more user friendly. $900 vs $500 and the reagent costs are the same.I think I'd be happy with either unless in the future I get a GHL controller.
 
I have a KHG. I found it interesting to see the trends and learn when my tank was consuming. But when I switched tanks I never set it back up again. my tank is an aio I need the khg above the tank and it is a bit loud if it isn’t in a cabinet so I haven’t installed it again.

I have had bad experiences with the ghl UI so I prefer the reliability of the khg interface, and it can be controlled with api. I also like that the waste water from a test can just go back into the tank instead of a waste container.
 
Well, technical aspects aside, it's a moot point now: https://www.reef2reef.com/threads/anyone-using-a-diy-reagent-for-kh-guardian.603631/ (starting on post #5).

In the user manual, page 26, they state that using non-original testing reagent can cause your KH Guardian system to become locked. To unlock it, you have to ship it back to Taiwan (presumably at your own cost) and pay a $100 unlocking fee.

Considering that the consensus seems to be the testing reagent is just 0.1 N of acid, this is absolute BS. I can understand it violating your warranty, but them effectively bricking your system is beyond the pale.
 
Well, technical aspects aside, it's a moot point now: https://www.reef2reef.com/threads/anyone-using-a-diy-reagent-for-kh-guardian.603631/ (starting on post #5).

In the user manual, page 26, they state that using non-original testing reagent can cause your KH Guardian system to become locked. To unlock it, you have to ship it back to Taiwan (presumably at your own cost) and pay a $100 unlocking fee.

Considering that the consensus seems to be the testing reagent is just 0.1 N of acid, this is absolute BS. I can understand it violating your warranty, but them effectively bricking your system is beyond the pale.
That's insane... How would a KHG even detect that it's the "wrong brand" of acid?
 
That's insane... How would a KHG even detect that it's the "wrong brand" of acid?

Someone in a thread mentioned viscosity as one potential way. It's also possible there's an additive (luminescent, colormetric, etc) in the reagent that's not there in 'stock' acid. Or it's possible this is just a scare tactic.

Either way, the fact it's official policy has permanently put me off buying one of these instruments.
 
Yeah that's some straight up John Deere level of bullsh*t for the hardware, and the way they try to defend it "it's for the safety of the user... and to protect our product" That last bit is probably where it happens, but "their product" is most like the continued income from people using the unit, akin to a subscription fee.
 
Putting aside profits from consumables, I can see them getting sick of excess customer support and negative reviews from people putting the wrong reagents in and having it get damaged or not work reliably, assuming that that happens. This lockdown/scare tactic may work ok in other cultures but not ours.

They have other reasonable approaches they could have taken- making their reagents cost-competitive, making them truly unique, publishing exactly what they are and how to make your own, or just saying use of DIY reagents voids your warranty because they damage the unit (if they do).
 
The printer model. Discount the unit heavily and make up the profits on the consumable. Not particularly a fan myself but was not aware of this prior to picking one up.
 
Well if the unit was in the same cost basis as inkjet printers then I could at least partially identify with it :), but they're not cheap from the get go.
 
Putting aside profits from consumables, I can see them getting sick of excess customer support and negative reviews from people putting the wrong reagents in and having it get damaged or not work reliably, assuming that that happens. This lockdown/scare tactic may work ok in other cultures but not ours.

They have other reasonable approaches they could have taken- making their reagents cost-competitive, making them truly unique, publishing exactly what they are and how to make your own, or just saying use of DIY reagents voids your warranty because they damage the unit (if they do).

Regarding reagents being cost-competitive, I do want to note that they're not that expensive - $35 for 45 days of supply. But I completely agree with your other points.

While the units are not cheap, I feel like they are lower-cost compared to alternatives (a KH Guardian can be had for (I believe) sub-$500, which includes the tester and an extra doser, compared to ~$850-900 for the director). I suspect, particularly given the reported quality, they're loss-leaders for the reagents, but this is just conjecture on my part.
 
Well if the unit was in the same cost basis as inkjet printers then I could at least partially identify with it :), but they're not cheap from the get go.
I decided against a 2nd unit for the 75g because of the reagent cost doubling to $30 a month. Nowadays that's the cost of a large pizza but still... this hobby has a high recurring expense cost as it is.
 
I decided against a 2nd unit for the 75g because of the reagent cost doubling to $30 a month. Nowadays that's the cost of a large pizza but still... this hobby has a high recurring expense cost as it is.
See that's why you tie all your systems together into one common water supply, and then call yourself a LFS :)
 
Normally I don’t post. I just read. But I do have something to say about the KH Director. It sucks. They are like a BMW that needs service. When they work. It’s nice but when it doesn’t. They are a pain in the butt. The app is horrible. You have to be a computer guy to understand it. Everything has to be spot on and the stars have to be all aligned to get a accurate reading. Then when you do. You better not touch anything or you numbers will be off again. I always compare it to a android phone. There’s a lot of stuff to figure out. You can find them used for 550. With the 2.1. And you can use generic solution from Amazon. Which is cheap. But other than that. It’s a pain.
 
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