Looking for insight to discrepancy in Water Parameters

[AFTICA]

I am looking to getting some Discus in the comming month or so... and I am in the process of preparing for thier arrival. I had Discus up untill about 5 years ago in my CO2 injected planted tank... had them breeding in there as well... so this time around I am looking at having a go at breeding them and going Bare Bottom etc..

So I set up my 75 gallon which I want to fill with 8 or so younger discus (3½ - 4 inch) - and it is now running.... Filled it last night... added 400W of heat on a Medusa controller (Temp steady at 82º) ... added a Hydro II sponge filter and an Aquaclear 70 with 2 sponges and a bag of Fluval Biomax. Getting ready to do my Fishless Cycle.

I decided to do some Baseline water tests this morning.... using several kits and a Hanna meter... and I got some conflicting results... not major but would like some insight from the more experienced in Water Parameters and Meters etc...

Here are the results... (from the tank after 24 hours)

PH Tests
API Test kit (6-7.6) 7.6+ (Seemed a little deeper than 7.6 but that is the max for this kit)
Nutrafin (6-7.6 kit) 7.6
Nutrafin (4.5 - 9.0 kit) 7.5 (the kit measures in .5 increments so it is 7.0, 7.5, 8.0 nothing in between)
Hanna 98129 Pen 8.30 (I just calibrated the brand new meter via 7.01 and 4.01 solutions)

Perplexed on that reading... I checked my PH direct from the tap and it was 7.97 (cold only 56º) and warm from Hot water boiler/cold mix 7.93 at 78º (Using the meter!)

I cannot seem to explain this... New Meter just calibrated... could the probe be bad? Otherwise I don't see what is raising the PH in the tank, that only the meter is reading?


The rest of the test results:

Nutrafin test GH = 5 drops x 20 = 100 PPM

Nutrafin test KH = 8 drops x 10 = 80 PPM

Hanna TDS 125 PPM or 250 µS EC

Nutrafin Nitrite = 0 PPM

Nutrafin Nitrate < 5 PPM

API Ammonia test = 0 PPM

[Eddie]

Are those test kits new?

[AFTICA]

Yepper - the nutrafin ones actually publish a ledgible expiry date on them (wish API did that)

They don't expire till 2014 sometime.

[Eddie]

Then to me it seems your Hanna Pen might be off since you used 3 other test kits and they were similar.

[AFTICA]

Then to me it seems your Hanna Pen might be off since you used 3 other test kits and they were similar.

I suspect you are correct... thinking back I used a fresh 7.01 solution packet from Hanna but my 4.01 packet from pinpoint was several years old. They are sealed individual packets and of course - not dated with a date code that the consumer can read etc...

Will need to order some new ones I guess.