When is the best time to do testing?

sghera64 · Jun 25, 2020

Just a theory here, but I can conceive a mechanism where the time of day, and how far into the lighting cycle things are, could matter for tests like NO3, CO3 and pH is a given.

Intense lighting fuels micro fauna metabolic activities. These consume CO2 and raise the pH. This is certain. Tanks with lots of zooxanthellae and other algae may see an impact on NO3 and CO3.

These effects may be offset in some systems by CO2 reactors, algal scrubbers, refugium, dosing and other countermeasures employed by reef keepers. This is especially true if employed with timers to deliberately balance out the diurnal cycle.

One last consideration is the accuracy of our tests. The variations corresponding to when in the lighting cycle you sample and test may be too small for hobby grade tests to accurately pick up unless the system is kept very constant and a lot of sample data is generated and statistically analyzed (e.g. t-test).

To spot real trends, I would recommend testing at the same time of day. This removes lighting cycle as a factor.

X-37B · Jun 25, 2020

Alk in the morning.
Ca, mag once a month.
Po4 only if something looks off. Same with no3.
I do test all once a month and log the results.
Not sure why so many people have issues with Hanna.
Its what I use for alk and p04.
Alk is always accurate and cross checked with Salifert and Elos if I get an off reading.
Rinse your vials and store them filled with ro/di after each use.
I have been using the same vials for over 3 years now.

Jax15 · Jun 25, 2020

I usually stick to mid morning, before feedings. I don't worry too much about timing beyond that. The trick is to just take notes, I log them in Apex Fusion which is really helpful for adjusting dosing.

Sidenote, I've always found my Hanna Alk checker to be rock solid. ULR Phos is pretty good, don't trust it 100% but closer than I've found with any other Phos test. But Alk, yes, no other way for this guy.

neoGeorge · Jun 25, 2020

neoGeorge said:
Hello All:

I use a spread sheet for testing to track results and to comment on any observed reef issues (image included below). I don't test on a scheduled basis, or at a scheduled time - it's more based on when I make the time, or more importantly, if I observe an issue with the reef.

In the Header row, I detail my target numbers for ALK, CA and MG, and also the dosing times for the 2-part and Tropic Marin Part C: this allows me to see at a glance if parameters are trending away from my initial targets, and also reminds me when each component was last dosed (if I'm testing right before or right after a dose is scheduled, I mentally adjust my expectation for the corresponding test result).

I'm a big fan of the BRS video series, so I try to adopt their best practices, but also give myself leeway with the understanding that this is a hobby (this shows up in my ALK swings and less than weekly water changes, for example). Always trying to improve my process, though!

Regarding ICP testing - I send in about one lab sample a year to Triton - two of the reports have mentioned levels of metals that could be harmful (most recently low-level tin), so this gives me a heads up to look for any obvious sources, like magnets or missing insulation. A couple of years ago the ICP report mentioned high levels of tin and I discovered that the inline JBJ UV sterilizer was not water tight and contaminated the tank water.

Anyways, the magnetic stirrer has made testing much easier, and when combined with an Arduino based testing prompter, testing is much less of a hassle.

For anyone looking at the details on the spreadsheet, which is unlikely, but just in case, the snapshot shown was during a really trying time for the tank, which is why there are so many red and yellow colored cells. A month or so before this period, two Chromis that I purchased online died at night in the rockwork, and although their bodies never surfaced, nitrates went from about 1 to about 15 and to this day are still in the 10 range even with the long term NOPOX dosing regimen. I dosed Vibrant at 5 ml instead of the usual 2 ml (every 2 weeks for a 65 gal tank). Phosphates plummeted to 0, then came the cyano, then came phosphate dosing to bring the phosphates up and using CyanoClean to remove the cyano - many of you know this drill...