Thinking about a digital colorimeter, anyone actually trust theirs

Started by Priya Raman · · 5 replies
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#1
I test by hand weekly with the Taylor K-2006 (FC 4.5, pH 7.6, TA 80, CYA 45, pretty steady lately) and cross check with my Ondilo ICO for trend data between tests. Been eyeing one of those digital colorimeters for FC and pH just to cut the color matching guesswork out of the equation, especially on the pH side where I know my eyes are the weak link.

Anyone running one alongside a reagent kit, how close do your numbers actually come out. Not looking to replace titration entirely, more curious if it's worth the money as a tiebreaker when my eyeballing feels off. Anecdotally my manual FAS-DPD has been solid all season so I'm not desperate, just curious if this is a real upgrade or a gadget solving a problem I don't have.

5 Replies

#2
I don't have a colorimeter so cant speak to that specifically, but the pH color match being the weak link rings true, thats the one I squint at the most too even with the K-2006. If your FAS-DPD has been solid all season I'd honestly save the money, sounds like you already solved your own problem lol.
#3
Priya, before you spend money on that thing, what exactly is bugging you about the pH match, is it the 7.6 versus 7.8 type call or are you getting readings that swing all over.. if its just the fine line between two close shades that's your eyes doing their job, not failing you. I've been reading that same Taylor style comparator for thirty years and my eyes aint what they used to be either, but the pH block don't lie once you know your own water's tint.
#4
It's more the 7.6 vs 7.8 call than anything swinging wildly, Earl, so maybe that answers my own question honestly. I've got the acid demand dialed in enough that I'm rarely further off than that half step, and the ICO backs me up on the trend between tests so it's not like I'm flying blind on it.

Think I talked myself out of it typing this out, actually. If my water tint's consistent enough that the block reads the same way every week (and it has, n=1 but a whole season of it), that's not a hardware problem, that's just me wanting a number with a decimal on it for its own sake.
#5
Yeah you answered it, half a step on pH ain't worth chasing with more hardware. I carry a K-2006 on the truck for 80 accounts and never felt the need for a colorimeter, the comparator's been dead consistent on my own pool all season too, decimal point or not it's not changing what acid I dose.
#6
Ha I did the same mental math with my pH strips before I ditched them for the K-2006, kept thinking I needed something fancier to fix the guessing when really the problem was the strips themselves, not my eyes. Once I switched to the comparator the color match got way easier to call consistently, pretty much what tampapoolguy is saying, it's dead reliable once you know your own waters tint.

Sounds like you already have that part down with the K-2006 though so this isnt the same situation at all, youre just second guessing a half step thats probably fine. If the ICO trend data lines up with what youre seeing week to week I wouldnt spend the money chasing a decimal, anyway, sounds like you already made peace with that typing it out lol.