The step to take the week after introducing your CUC...

Sk8r

Staff member
RC Mod
This would be a real good time to start your alkalinity tests. Salifert is the brand I use, dirt simple, numerical (which you need) and fast.

During cycle, you learned to test for nitrate and ammonia. Nitrate is a good thing to do from now on, even if you're a reef. It can really creep up on you to disastrous levels and give you failure-to-thrive with corals.

But alkalinity now becomes top of your list. If it's off you have unhappy fish, unhappy everything. So set up a testing schedule, a day and a time you won't forget to do it, such as right BEFORE your weekly water change. A fish-only should test alk, nitrate, and ammonia every week, and more often and more kinds of tests if things aren't right. Write down your result in numbers, so you can tell if it's .001th upward or .001th down this week.

For those headed for reefs, you can test nitrate once a month under most circumstances, unless it's high (over 20) and if you're doing fussy corals, make that (2). But alkalinity---matters a lot.

Where should it ride for either kind of tank? Between 7.9 and 8.3 for most purposes. It'll be ok to have it higher---up to, say, 9. But not lower.

What is alkalinity? It's kind of related to ph---measuring the capacity of your water to neutralize acid. It measures sensitivity of the liquid to acid inputs. [Wikipedia]. What this means for your tank is, one surmises, it measures your water's ability not to dive for a really bad ph. This is WHY alkalinity, not ph, is the thing to track. Having something to measure ph is useful. Having a test to measure alkalinity is critical.

What do you do if your alkalinity is too high? Water changes and patience. It will tend to fall over time.

What do you do if your alkalinity is too low? Real easy. Add DKH Buffer, according to the instructions on the container. Kent is my brand of choice, but there are a number of good brands.

Go ye forth and just remember---once you've cycled, you've got a brand new test to do weekly. IF every newbie would do it faithfully and ride that 8.3 as closely as possible, it would help keep tank water much more stable, fish far happier and healthier, and it would mean far fewer 'agony posts' in the NTTH forum.

If you have trouble HOLDING that 8.3, there is a fix for that: raise your magnesium to 1300 and your calcium to 420 and by a miracle of what keeps the oceans steady-on, it will balance the alkalinity at a steady level: ask in the chemistry forum if you need the why. Just take it that it works. And it's often the difference between a tank that flourishes and a tank that just has constant ghosty trouble.
 
What happens of your makeup water is high on alkalinity? Say 12dkh. Wouldn't doing water changes raise the alkalinity in your tank if it's at 8?
 
Hi Sk8r

I've enjoyed reading your recent posts, very helpful. I've started testing Alk since my cycle finished and have been getting 7.7, which is what the salifert test days is typical ocean level. Why do you recommend 8.3 and should I look to increase mine to that sooner than later? I currently only have the start of a cuc and planning on a softy LPS tank with maybe a couple of small fish.
 
8.3 is useful with corals: I'm used to the balance of 8.3 alk, 420 calcium, and 1300 magnesium: it's been very good for growing lps, and if you hit that, you can get that to hold steady for a month on end if you just keep replenishing fresh water laced with kalk powder (calcium). At those readings, even with a tank full of stony coral, the alk/cal/mg ratio locks, and nothing will fall but mg, which goes very slowly compared to other elements---when it drifts much below 1300, then the other two will start to fall. This lets you go on vacation for a whole month without sweating it if you have an autotopoff, and can autofeed fish food or get a reliable neighbor.

Now, whether other proportions will 'lock' like this I don't know. {Dang it, Jim, I'm a doctor, not a ---] I leave you to ask that one in Reef Chemistry. But I recommend a relationship I know can keep you pretty well able to go off and leave a reef in the hands of a tanksitter with no fear.

As an added note, at that reading, you will have NO trouble growing coralline: just watch it with acrylic tanks, and scrape it off early and don't let it build up.
 
What happens of your makeup water is high on alkalinity? Say 12dkh. Wouldn't doing water changes raise the alkalinity in your tank if it's at 8?

Some salt mixes run a little higher than ideal to make up for the tank consuming alk, ca, and mg. The idea being that between water changes those levels will drop, and having extra in the salt gets you back in range. It's not ideal to have things bounce around like that, but sometimes it's ok for reefers that don't quite have enough coral to dose those elements, but do need to pick up a little slack.
In those tanks, if the alk were 8 of the new salt water, the alk in the tank would drop over time as it were consumed and not replenished (unless you were changing 100% of the water).

Assuming you are using rodi, so all the alk in the water is from the salt mix.
 
This was very good to know. My tank has been up since July 2014. I haven't been testing for anything accept calcium (occasionally) and phophates (daily). I use the calcium and phosphate tests to tell me if I should do a water change or supplement calcium. The reason why I haven't tested for alk is I would not know what the reading meant or what I should do if they were off. Now I know. Thanks for the info.
 
Coming back to this one... sk8r, you have mentioned In a couple of Ithe post about "tossing" Kalk in the ATO but I've never seen any reference to amounts? When you say Kalk, what is the product you recommend?
 
Quite a few folks, myself included, use Mrs. Wages Pickling Lime (purchased from most big box grocery stores/retailers...i.e. Wal-Mart or Target) and start with 1tsp per gallon of top off water.

There is a solubility limit, so you cannot overdose; anything extra will precipitate out and will dissolve as you refill the ATO container.

Dosing kalk in an ATO does impact the longevity of your ATO pump...not a lot but enough that you will most likely replace that pump a bit more often than normal.
 
^this. I don't even bother to measure, because the water itself can only take 2 tsp per gallon. Anything left over falls to the bottom: just don't let your ato pump suck it up into your tank.
When you add more ro/di to that reservoir, more kalk dissolves just like that. You only need to stir it that one time, and it's good. You don't want the white residue kicked up: let it lie there. BUT do lid the reservoir, with kalk, or it reacts with the air and makes a gunky stuff on the surface.
 
@ silent_circle and @UBOMW sounds like you may be using a salt mix that has the high levels. IMO, sounds like you are using Red Sea Coral Pro Salt which has high parameters. Some hobbyists use Instant Ocean and adjust as necessary. I suggest finding a salt that is close to the parameters you want and make adjustments from there. Hope that answered your question.
 
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