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pH drop meeting resistance...

I am also using the intaqo and what I did was to set the pH interval (in my case 6.2-6.3) and not kH, which I’m my case corresponds roughly to a pH drop of around 1. I can see that during the night, my tank does not fully degass since my degassed pH is around 7.2 or so and I am getting only around 6.9

I use a CO2 reactor and you need to open the valve more so you alway reach the target pH. I saw conflicting evidence whether it was better to have a continuous flow of CO2 (solenoid always on but low bps) vs bursts of CO2 (solenoid on with higher bps for small periods but several times a day).


As mentioned kH might as well change during the week with accumulation of fertilizers (depending of what you are dosing), leaching from rocks, etc.. so the values you reach each day might vary but probably will not have too much impact over a week time.

Also bare in mind that the kH/pH/ppm of CO2 charts are not very accurate since they do not account for all the other factors that do interfere with pH, like tannins, nitrates, etc… hence why people aim for 1-1.1 pH drop instead of following those charts.

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I have been using the Hannah KH Pocket Checker colorimeter quite successfully. It has decent accuracy at 0.1 dKH.

Just measured my Tap water with it and I get a reading of 0.6 dKH (TDS is 33ppm). Testing my Tank water and it reads 10.4 dKH (TDS 430ppm). It appears as accurate for Freshwater as it is for Seawater.
Hi @X3NiTH

Are you using the HI-772 colorimeter? If so, it is supposedly "Designed exclusively for saltwater aquariums, the HI-772 checker offers a quick, easy and highly accurate method of measuring alkalinity in degrees of calcium hardness, commonly abbreviated as dKH". And, something doesn't tally. Looking at the ratio of TDS to dKH for your tap water, it is 33:0.6 = 55. And, for your tank water, it is 430:10.4 = 41. Right now, I'm not sure what the explanation is for this. Rightly or wrongly, I was expecting the two ratios to tally. It must be something related to the composition of each water sample.

JPC
 
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Yes it’s the HI-772 for Aquariums and Marine Use and as you can see I’ve just used it successfully to test two vastly different freshwater parameters and gain an accurate result (in comparison to JBL Test strips ballpark values). Freshwater use titration tests for dKH on my tap give a reading between 1 and 2, this measurement is including the alkalinity effect of hydroxide moderation of the water to artificially increase the pH to Neutral for distribution network corrosion prevention, the use of the Hanna checker fluid being low molar HCl neutralises this component thus should only be measuring carbonate as a function of CaCO3.

You have noticed that there isn’t a correlation between my tap values and the tank values and that would be because the tank is remineralised RO initially to a KH and GH of 8, TDS around 160ish at start and has been going a full year without water change while dosing EI, CO2 and overdosing Liquid Carbon (Microbe-Lift BioCO2), zero plant maintenance, all plant decay has remained in situ to become part of the total concentration of elements comprising the current water chemistry, hence increased GH, KH and TDS, I am not dosing calcium or magnesium, my Macro solution is undiluted BioCO2 dosed at 1ml/10L every other day fortified with added KNO3 and KH2PO4, all the chelates in use are biodegradable and non accumulative (DTPA, Gluconate, Humic Acid, Fulvic Acid and Citric Acid). No idea about the concentration of metal elements available but the snails seem not to mind it.

:)
 
Just a thought... cheapo tds meters and ph meters are fairly consistent at measuring changes, it's the consistency that counts, the actual reading is mmm, meaningless in a planted tank. Again just a thought...
 
Hi all,
the use of the Hanna checker fluid being low molar HCl neutralises this component thus should only be measuring carbonate as a function of CaCO3.
New one for me, but it would make sense.
cheapo tds meters and ph meters are fairly consistent at measuring changes
Cheap conductivity (TDS) meters should be reasonably accurate (although ideally you would want a low range meter and automatic temperature compensation), but I wouldn't ever recommend a cheap pH meter.

cheers Darrel
 
Fair enough darrel, I just worry that people new to this think they need to go out and buy the latest all singing, all dancing machines that will qive readings to the nearest 0.001.

If these high quality machines probes aren't stored or calibrated at each point of use(which they're often not) then the accuracy is lost, and they might as well buy a reasonably priced monitor and accept it will give satisfactory readings, albeit not 100% accurate.
 
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New one for me, but it would make sense.

I’m being a bit naughty here because I’m making statements from assumptions based upon effect and trying to work backwards to find the cause. The device is designed to measure Alkalinity as a function of CaCO3 in seawater so that correct dosing of carbonates can be made to keep carbonate alkalinity stable in a reef system, as alkalinity has hydroxide as a component this would fudge the numbers and because the amount could be variable you would need to neutralise it to discover the alkalinity only as function of CaCO3 hence acidifying the sample with a consistent known total amount of acid (1ml reagent to 10ml sample), the resulting colour sample shifts from yellow to blue on the indicating spectrum depending on the hardness. I’m guessing at HCl being the acid in question only through comparison to what can be used if using a KH bot and we’re looking for a DIY route to inexpensive reagents, (for instance here on Reef2Reef).

Taking all this into consideration I’m making an assumption precisely because ‘it makes sense’. There will be a paper out there somewhere on this that would clear up any misconceptions but I haven’t found it yet or tried hard enough to look.

:)
 
You can see what the graph looks like now that CO2 output has been increased. The 1.0 drop is being achieved, the drop checker is light green and the pH is stable from lights on 16:00-22:00.

Be careful that if you’re KH is climbing during the week and you consistently hit the same pH by controller then by the end of the week the drop checker could be indicating yellow showing increased CO2 in the water.

:)
 
Just a thought... cheapo tds meters and ph meters are fairly consistent at measuring changes, it's the consistency that counts, the actual reading is mmm, meaningless in a planted tank. Again just a thought...

I agree. For TDS, all I need to see is the trend up or down, though the movement does seem correspond to expected values. When I measure TDS with my cheap meter before and after adding Epsom salts, for example, I find the TDS meter registering a fairly 'accurate' increase in ppm. Same when I add my all-in-one Fert.
 
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