KH Guardian: Automatic Alkalinity Controller- My Experiences
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jsker
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cought up
12 days, and allot happening
12 days, and allot happening
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Rick.45cal
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I believe they are currently looking into that
rockworm
Active Member
I have been following this thread and may have missed it, but has anybody posted what the volume of RODI is for 1500 grams? I am not a scientist, but it seems to me that the conversion would be the same whether I am in Canada(which I am) or Europe.
rockworm
Active Member
Thanks guys. I may have to go get a scale. I just find it unusual that I have to measure a liquid by weight, rather than volume. For me, this is disappointing that the vendor has not willingly provided a conversion. There may be a reason that I am obviously not aware of.
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Rick.45cal
2500 Club Member
I'm waiting for the 1kg and 2kg calibration weights I need to calibrate my new set of electronic balances so I can measure it out accurately to +/-0.1 g.
I'd offer to give you a measurement in ml, but there is no method of volumetric measurement that is accurate enough. Volumetric flasks have an inaccuracy larger than that. So anything that you measure out using any container by volume, is going to give you an inaccuracy.
My first batch of reagent is flawed because I measured 1500ml by volume, and not 1500 grams. So I want to make sure that reagent from now on is measured accurately.
rockworm
Active Member
Thanks Rick. I truly appreciate your input in documenting your journey with the KH Guardian. I plan to set mine up this weekend. I just find it frustrating that the vendor cannot provide a conversion from grams to mls.
If the vendor plans to market this to the average reefer then, in my opinion, they have missed the mark by requiring users to go buy a weight scale. I have yet to go and ask for 25 kilograms of gas for my car. I buy it by the litre. Why should I, as an average reefer, have to get a scale to weigh water.
This is a customer service flaw and unless Coralvue, or the developer, can explain why a grams to mls conversion on RODI varies by region, then they are forcing additional and unnecessary (weight scale) costs on the user.
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Rick.45cal
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Volume of water is influenced by temperature, as temperature fluctuates so does the volume of the water. Mass is constant. So 1500grams of water is the same all around the world. But 1500ml isnt' 1500grams depending on what temperature the water is. Add that fact with the fact that a volumetric flask (the most accurate way to measure volume) will have an inaccuracy of +/- 3 ml.
So really there are only two options here. Have the customer weigh the water for the reagent and add it themselves or ship 1.5L of reagent across the globe that's been preweighed.
Personally I see the way they are doing it as a distinct advantage to us as the user. Anything to keep the price of the reagent as cheap as possible is a plus in my book. In the long run it will help keep costs lower, and it's a lot easier for me to store 5-10 of those little reagent packets than the equivalent if it were premixed.
Buying an electronic balance and calibration weights for me is not a huge deal, I will use it all the time making solutions. I've already figured out that it will simplify making solutions for me. I bought a 1 L volumetric flask so I can make DIY solutions based off of molarity and then it becomes very simple to calculate how much to add to affect the needed change in ppm (or whatever unit is used).
I totally understand your frustration, but I think the reasons that they did it this way is actually a big advantage it just doesn't appear that way upon first glance.
rockworm
Active Member
Again I thank you because you provide me valuable insight. However, I am an average reefer who does not even know where to get a scientific flask. I am an accountant and not a scientist. I did expect the volume vs. temperature issue to raise it's head and I have enough understanding of physics to know volume changes with temperature. If we have to be this precise then again I ask, what is the average reefer suppose to do? Users will be required to buy scales in addition to the KH monitor.
I have the resources to implement the Guardian using weight vs volume but I feel that this should not be necessary. I have spent a lot of money buying this unit (US$ conversion, taxes, import) so why can't the developer and supplier provide us with some conversion rates?. We have spent much money to be the guinea pigs, so maybe the developers could spend a few bucks to provide a temperature/mls/grams conversion.
I am not averse to new technology. I have always jumped on the leading edge. I was one of the early adopters of the PFO Solaris LED's and while it did not work out for me, it did not deter me from trying other new things.
It is time for the KH Monitor developers and marketers to find a way to make the equipment far more user friendly.
I have 400g SPS and 75g LPS tanks and I see alk monitoring as extremely beneficial for me. I am only expressing my concerns as a non-scientific reefer.
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Rick.45cal
2500 Club Member
I think those are all very valuable important points that they need to consider! I also agree with you. I tend to be the very chemistry oriented reefer, and not everyone is like that. They will need to market to the non chemistry oriented reef keeper if they want to sell the most units.
The KHG definitely has some bugs that need to be worked out IMO, but it really works and it's great not having to worry about alkalinity dips, or even testing. Big lifestyle change! To top it off, the growth I am getting now is nothing short of miraculous compared to what I had before. My alkalinity consumption has been on a steady increase. It's also given me the confidence to take on some more frags, so it will be interesting to see how they settle in.
I'm hoping that there are some big changes, including a fix for the strange absence of KH values in the display, in store for the future. I suppose time will tell. Maybe @eltonw will share with us some of his insights.
The KHG definitely has some bugs that need to be worked out IMO, but it really works and it's great not having to worry about alkalinity dips, or even testing. Big lifestyle change! To top it off, the growth I am getting now is nothing short of miraculous compared to what I had before. My alkalinity consumption has been on a steady increase. It's also given me the confidence to take on some more frags, so it will be interesting to see how they settle in.
I'm hoping that there are some big changes, including a fix for the strange absence of KH values in the display, in store for the future. I suppose time will tell. Maybe @eltonw will share with us some of his insights.
rockworm
Active Member
I have expressed my disatisfaction with some aspects of the initial delivery. However, I am anxious to implement the Guardian this weekend because I know my 400g SPS will so much easier to manage.
This is a game changer and I am so looking forward to such steady parameters. I use a CARX and will use the KH monitor to dial in the level.
This is a game changer and I am so looking forward to such steady parameters. I use a CARX and will use the KH monitor to dial in the level.
rockworm
Active Member
I believe I will be happy with the results. I have followed this thread and there are a few anomolies but a new tech always has some problems. From what I have seen from the posted results of users, I should be able to see a consistent alk level in my system. It will just take a few adjustments that I expect as a new user.
I am not dissing on the KH Guardian. I have only provided my observations as a buyer and average user. Alk monitoring has so much potential for SPS reefs that I am willing to make this investment and I will provide the feedback once I implement it.
No conversion table is needed. 1.5kg of RO water is equal to 1.5L. Yes, in theory the density of water changes with temperature (and atmospheric pressure), but not by enough to make any difference. Neither household scales nor household measuring cups are accurate enough that reasonable temperature differences would need to be accounted for. The reason why they say you should use a scale is that you can pick up a kitchen scale at most grocery stores for $20 that can measure 1500gm reasonably quickly and accurately. While you are not going to find any way to measure 1500ml with anything approaching that level accuracy without speciality lab equipment.
But really it should not matter if your reagent is off by 1% or 30%. It makes absolutely no difference what the strength is. As long as the strength is known (and the strength of the reagent can be determined by using the reagent to test a solution with a known alkalinity). No matter how far off your reagent is, as long as you calibrate the machine you should end up with an accurate reading. And on top of that - there is a huge range in acceptable alkalinity values. Stability is far more important than any particular value. As long as you are not aiming for the absolute top or bottom of the scale, even if the reagent is off by 10% and you don't calibrate and therefore the absolute alkalinity value is off by 10% it would really matter.
All that said, I totally agree that they should offer pre-mixed reagent as an option. Yes it would cost more, but this is a $1000 machine - people who are super sensitive to the cost are not buying this thing. There is no reason why they can't offer both options and let people who are willing to pay more for the convenience do so.
Or they could solve the reagent mixing problem with a simple software tweak. They could use the same pump that it uses to dispense the reagent into the test vial to dispense 1500 ml of RO water into your reagent reservoir.
This should actually result is measurements that are MORE accurate than measuring the 1500gm of RO water with an ultra-precise lab scale. If the reagent pump is off by 1%, and your reagent mix is perfect you get results that are off by 1%. But if your reagent pump is off by 1% and your reagent mix is also off by 1%, you could get results that are perfect.
This should actually result is measurements that are MORE accurate than measuring the 1500gm of RO water with an ultra-precise lab scale. If the reagent pump is off by 1%, and your reagent mix is perfect you get results that are off by 1%. But if your reagent pump is off by 1% and your reagent mix is also off by 1%, you could get results that are perfect.
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rockworm
Active Member
@cypho, thank you. This makes the most sense to me. I knew there were variances due to temperature, but I could not wrap my head around a few degrees difference and changes in alk. My house is maintained +- 3°f year round so my tanks at least maintain the average house temp. I intend to go with 1 ml = 1gram for the reagent and will see what happens with this ratio.
If this does not work out properly, then Coralvue and/or the developer better provide a proper ratio of reagent to RODI under variant temperatures.
If this does not work out properly, then Coralvue and/or the developer better provide a proper ratio of reagent to RODI under variant temperatures.
https://www.ncsu.edu/chemistry/resource/H2Odensity_vp.html
At room temperature the density is actually 0.997. But you are not going to be anywhere close to accurate enough with your measuring cup for that make any difference.
If you get poor results (which would surprise me) it will not be because you did not account for the temperature. It will be because you did not measure 1500ml accurately.
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Rick.45cal
2500 Club Member
The best plan short of using a scale is to use as accurate of a measuring device as you can, measure the entire volume in a single container, and always use that container for making the reagent. Then at the very least you will be consistent in your reagent and it won't matter that much.
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