CYCLING isn't the end of it: Water parameters: a quick reference

[Sk8r]

For a fish-only: 0 ammonia, 0 nitrite, close to 20 nitrate as you can manage---or lower; salinity 1.019 to 1.026 but STEADY: never vary salinity more than .002 in any water change. Alkalinity s/b 7.9 to 8.3, as high as 9 ok. Don't chase ph: that's not as good a practice in salt water as it is to keep steady alkalinity. If alkalinity falls, DKH buffer or 2 part dosing. A fish-only salt is fine.

For a softie reef: roughly the same, but 2 is a better nitrate reading; and salinity needs to be 1.024 to 1.026, never rising more than .002 at a go. Alkalinity should be about 8.3, as with fish-only. You will need alkalinity buffer, and do your water changes. Use a reef salt.

For ANY coral that has a hard skeleton---aka a stony coral---you need a strict water balance and nitrate around .2 (point two); Salinity same as softies. Alkalinity s/b 8.3, magnesium 1350, calcium 420. The lighting is the source of much of the coral's food. Stony includes both sps and lps corals, and the main difference is that sps lives far more on light and needs crystal clear water to be sure it's getting that: filter socks and a very good skimmer help. Kalk in the ATO is the easiest way to deliver calcium supplement. If you need to restore stability, dose mg first, then alk buffer, then calcium, and wait 8 hours between doses even of the same stuff: takes a while to dissolve and work its way through the chemistry.

Stability matters: bouncing the numbers around is not good. Keep your ungloved hands out of the tank: corals don't like our skin oils. And start a coral low in the tank and raise it gradually to be sure of the light level.

There are tanks that succeed with a little different readings, but these are here for easy starter reference. Check out the coral specialty forums for more variations and advice.

And, btw, when you test---a phosphate test can read 0, but if your tank is wide fields of waving green, you do have plenty of nasty phosphate: it's just all bound up in the weeds. GFO reactor will save you. Things that eat it just poo it back into the water. And if you can't get nitrate down, after trying everything---look to a more efficient skimmer. Best advice I have.

When you are just starting out, testing EVERYTHING is not bad, especially your nitrate/ammonia, salinity and alkalinity, plus temperature, and testing them daily before adding fish and such is not a bad idea. Writing down the result will show you trends, such as whether your readings are rising by a point or falling. This may be somewhat meaningless to you now, but after a while---you KNOW how your tank responds.

TESTING ALK
When your tank matures a bit you can settle into an easier routine. For example, the alkalinity test is the easiest. I know on the Salifert test, I can run the whole thing in a few seconds---scoop up a syringe of water, shoot it into the vial, add 4 drops, fill syringe from bottle 2, and shoot it into the blue-dyed water until it 'flashes' pink. Then slow down and go pretty well drop by drop until an exact result by the provided chart. However you test, the alkalinity test will tell you several things:
If it's between 7.9 and 9, your ph isn't likely awful; your magnesium is over 1200, and your tank will be fine.
If it's over 9, all the same is true, but you do still need to check it next week. If it's consistently too high, you may need to check your magnesium level, and if IT is too high, you may want to change brands of salt. Instant Ocean has lower levels of both.
If it's under 7.9, or your log records have shown you a steady drop over the last week, check your mg level, fix that, then once it's back to 1350, 8-12 hours later, add buffer. I like to keep my alk at 8.3, which affords some wiggle room.
TEST ALK every week, and whenever things aren't 'right.' If you have to fix it, your magnesium is also too low: fix that first, then fix your alk.

2. calcium---test this monthly: 420 is a good reading for a STONY reef. And here's a trick: if your alk is 8.3 and your cal is 420 and your magnesium (mg) is 1350, your readings will ALL hold steady until the mg falls below 1200. So be sure what your cal is...but don't go crazy over testing it too often if your MG is ok.

3. mg---test this monthly, unless it's falling. 1350 is your target for a reef. If it heads downward, add a dose of mg. If your alkalinity is falling, it's BECAUSE the mg has run below 1200. And here's a real clever trick: keep the mg at 1350, and your alk at 8.3 and cal at 420 by adding 2 tsp per gallon of kalk powder to your freshwater topoff. As long as that powdered calcium stuff (kalk) is flowing into your tank, and the mg is up, the alkalinity will also stay up, because it's also being supported by the process. If your mg is up, and the kalk is flowing, EVERYTHING will stay stable. [Note: kalk is for keeping clams or stony reefs supplied with calcium. If you have only softies and/or fish, you don't need that extra calcium.]

If you are running kalk, all you need do is check your alk weekly or whenever you have a doubt: if it's still 8.3, your mg and cal are fine and you can skip those tests. If it's falling, check the mg first, and fix MG first, then fix the alk, then the cal---by adding teaspoons of supplement.

This way you can run your reef successfully on one to two tests a week: that alk test will tell how the mg is behaving; and if the mg is ok, your cal is probably fine, ditto the ph. Testing the nitrate will tell you how your skimmer is doing---good or not-so-good.
If you are seeing problems, yes, of course, test everything. Fix things.
But a reef can be easier than a fish-only if you have kalk in the ATO and a little black notebook of records on those tests. You may fine-tune this for various specialities of reef, but in general, if you keep things at these levels, you'll be good. In general, when setting a 'good' chemical level, keep things in the middle of the 'good' range---so that neither evaporation nor a slight overfill can take you out of the good range.