Hanna Alk reagent issues

tcoyle · Aug 18, 2015

Anyone have any issues with recent Hanna Alk reagents?

It seems the last 2 bottles I have purchased seem to test lower Alk when I get to about 1/4 of the bottle left. Start using a new bottle and my test show about a 3dkh difference higher then the 1/4 empty bottle.

twilliard · Aug 18, 2015

Possible reagent contamination?

tcoyle · Aug 18, 2015

twilliard said:
Possible reagent contamination?

Always a possibility, but I am careful to use the same syringe and vial each time and clean them both out very well when done.

ReefMadScientist · Aug 18, 2015

I've never noticed an issue with my kH Hanna. I've had a few. Is yours expired? I know you said its new but check the date. I've seen a few LFS selling old testing kits.

tcoyle · Aug 18, 2015

nope.. I go through about a bottle a month these days. Testing at least 3 times a week, some times more.

pelagic · Aug 18, 2015

They have changed the regent a while ago from what I heard. The old one would give you higher DKH readings.
There are might be other reasons

1. Shake it well before you use it, to ensure the solution is well mixed
2. Make sure the cap is closed tightly to prevent evaporation.
3. Make sure to clean the bottle after every use, plus, always have the 10ml mark face front (or same direction of your choose) when testing.

or you can get a calibration fluid to find out what's the issue. either the equipment or the solution.

tcoyle · Aug 18, 2015

Great suggestions.. Its just ask odd. That it starts out high and then goes low as the bottle gets empty. Try a brand new bottle and its back up again.

bknapp · Aug 18, 2015

Maybe your alkalinity is unstable, have you tested twice at the same time? Have you fully automated your dosing yet? I know you only had one dosing pump at one time.

I would suggest testing it against another Hanna checker and seeing what they both say. If you want to bring a sample over I could test it with my checker and a different bottle of reagent against yours.

tcoyle · Aug 18, 2015

Yes I have 2 dosers now. I know its not a stability issue as one day it was 7.5 with older reagent (1/4 way empty) then new reagent next day was 10dkh. With the older reagent it was stable at 7.5 for weeks.

I might do that Brandon.. Thanks!

bknapp · Aug 18, 2015

That is weird then. Have you contacted Hanna to ask for input/assistance? Maybe they have a solution.

hybridazn · Aug 18, 2015

Are you certain you are getting exactly 1ml of reagent in the syringe when the bottle gets low? I know a lot of times when I test low its because I dont get enough reagent in the syringe

tcoyle · Aug 18, 2015

bknapp said:
That is weird then. Have you contacted Hanna to ask for input/assistance? Maybe they have a solution.

That is my next play. To your original thought though. I have been battling my levels and not dosing complete equal parts as I was still using RSCP which has an elevated Calcium and Alk. I have since switched to 4:1 ratio of RSCP to regular RS. I knew something was up this week when I mixed up fresh salt with a 3:2 ratio and my ALK tested 7.2 which is not possible with RSCP that mixes up at 11 and RS that mixes up around 7.7.

hybridazn said:
Are you certain you are getting exactly 1ml of reagent in the syringe when the bottle gets low? I know a lot of times when I test low its because I dont get enough reagent in the syringe

Its possible, but with a 1/4 left it seems I have enough in the bottle, and appears to fill up the same amount in the syringe.

bknapp · Aug 18, 2015

You need to remember water changes can only move your parameters so far. Also, do you roll your salt buckets prior to mixing? How long are you mixing for? You could be precipitating while you mix.

tcoyle · Aug 19, 2015

Yeah I understand that about water changes. I roll and shake my buckets well and mix for 2 hours like RS suggests.

pickupman66 · Aug 19, 2015

You are supposed to roll and shake your salt bucket before making water? I didnt know this.

bknapp · Aug 19, 2015

pickupman66 said:
You are supposed to roll and shake your salt bucket before making water? I didnt know this.

Don't shake just roll the bucket, helps to redistribute any particles that may be heavier than others and settle towards the bottom.

jgraz · Aug 20, 2015

tcoyle said:
Great suggestions.. Its just ask odd. That it starts out high and then goes low as the bottle gets empty. Try a brand new bottle and its back up again.

I had same exact problem with my last bottle. Alk tested at 8 something then opened new bottle and got 11 something. Then I opened a second new bottle and it matched the other new bottle. Tried 1 more test with the old bottle and it matched the original 8 something.
Never followed it up but just for S&G I tried a API test and it roughly matched the new bottles.

tcoyle · Aug 20, 2015

jgraz said:
I had same exact problem with my last bottle. Alk tested at 8 something then opened new bottle and got 11 something. Then I opened a second new bottle and it matched the other new bottle. Tried 1 more test with the old bottle and it matched the original 8 something.
Never followed it up but just for S&G I tried a API test and it roughly matched the new bottles.

Sorry your having the same issue, but glad I'm not losing my mind. I have an email into them and I'll let you know if I find out anything. But from now on I guess I just toss it out when it gets down to 1/4 empty.

jgraz · Aug 20, 2015

tcoyle said:
Sorry your having the same issue, but glad I'm not losing my mind. I have an email into them and I'll let you know if I find out anything. But from now on I guess I just toss it out when it gets down to 1/4 empty.

Yes please do let me know what they say. I've been meaning to contact them but just haven't gotten around to it.