Ive for a pretty basic apex jr that doesn’t have any probes. With that, I’ve been testing about weekly for nitrate, ph, alk, and salinity. I currently don’t have phosphate, calcium, or mag tests so I’ve been going to my LFS about every month to test.
How often are people testing, I know this is something I can improve on.
Hmm. I'm thinking that your Apex Jr. should at least have a temperature probe. And looking through some of Neptune's old documentation, it does seem that the Apex Jr. did not have an BNC connection for a pH probe. However, if you choose to do so, you can actually add this capability with the
PM1 module.
I find pH to be a useful parameter to monitor simply to make sure that there's nothing seriously wrong with my equipment. A powerhead or skimmer failure will, for example, result in a noticeably lower pH from insufficient gas exchange. My most recent use of this parameter was when my alkalinity tubing on my DOS came loose from its fitting and was drawing air for a couple of days - the dip in alkalinity caused a lower pH that I was able to correct before major problems occurred.
However, the actual value of pH in an reef aquarium is only weakly important to the health of the overall tank. There are folks with spectacular tanks that go between 8.4 in the day to 8.1 at night, and there are folks running a calcium reactor with spectacular tanks where the high pH mark is about 8.1 and the low's 7.8 or lower.
As you've probably gathered from the responses to the thread, the true answer to the question of optimal frequency of testing, and what to test is "it depends". It depends on what you're trying to keep, how new your tank is, if you're trying to dial in dosing parameters or calcium reactor settings, whether you've added or removed a significant amount of livestock, and even if you've added or removed a significant piece of equipment.
So let's address this systematically. If you're keeping fish only, you probably only need to test the specific gravity once a week or so (presuming you use an ATO), and the only other kit you'll need is a nitrate kit to check the tank once a month or so to ensure that nitrate's not building up to dangerous levels. If you're just starting the cycle on a fish only tank, you might want to add Ammonia to the kits that you have to monitor the cycle.
If you're keeping non-coral inverts and/or soft corals, you'll want to add an alkalinity kit to the refractometer and nitrate kit from above, and test it once a week or so. While the softies don't need the alkalinity and calcium per se, certain popular inverts may require it, both for shell building and maintaining a reasonable pH. You may also want to add a phosphate test to you repertoire, and test for it and nitrates once every two weeks or so simply to avoid issues with overgrowth of algae.
If you're keeping LPS stony corals, you will definitely want to test calcium and alkalinity at least once a week. While most LPS corals are far less sensitive than SPS corals, they still depend on some degree of stability of alkalinity and calcium, and also require certain minimal values of both of these parameters - certainly at least 7 dKH for alkalinity and 380 ppm or greater for calcium. Nitrate, phosphate and magnesium can be tested once every couple of weeks or so, or potentially more often for the NO3 and PO4 if you're fighting an algae outbreak. While magnesium is important for a reef tank with stony coral's health, it is depleted rather slowly. If you perform weekly water changes, it's fairly unlikely that you'll need to supplement it.
If you're keeping SPS corals, particularly acropora, I would recommend all of the above test kits except that you will need a Hanna Checker ULR phosphate kit instead of a "drop type" phosphate kit, and you will likely get little use out of an ammonia test kit beyond initial cycling of the tank. Generally speaking, alkalinity stability with acropora is extremely important; many of us test this parameter every other day, calcium - weekly (simply because it's consumed more slowly), NO3/PO4 & magnesium weekly. At some point, if the tank has been around at least 6 months, growth of corals is stable and therefore alkalinity and calcium consumption is stable and you're the risk taking type, dropping back to testing alkalinity weekly isn't unheard of. But most of us with SPS are a good deal more OCD than that, and continue to test at least a couple of times a week just to be sure.
