Dosing just alk?

John3 · Jan 28, 2018

So I’ve read that most people dose ca and alk in a 2 part system. I’m using reef crystals for salt and I do weekly 20% water changes. My tank is 29g without counting the rock. It’s fairly stocked with corals at this point and everything is showing growth with some corals showing very good growth.

I find that my calcium barely drops over a week if at all but I find that I need to dose alk every day to keep it stable. Does that seem ok/normal? I find that if I don’t dose my alk drops about 1 per day.

hybridazn · Jan 28, 2018

I would double check the calcium readings with a separate test to just verify that is the case. If it is then just dose what you need to.

Justfebreezeit · Jan 28, 2018

If your alk is dropping so is your calcium. and 1 what per day? meg/l? .1 dkh?, 1 ppm/CaCO3?

In general though you shouldn't have any problems just dosing alk

WWIII · Jan 28, 2018

http://reefkeeping.com/issues/2004-12/rhf/index.htm

Cory · Jan 28, 2018

Calcium consumption doesnt read as obvious as alkalinity consumption if its calcification causing it. Calcium test kit samples ideally need to have particles removed by cebtrifuge or micron filtration or caco2 particles will confound it.

The formation of no3 will reduce alkalinity, but photosythesis will put back that alk when it consumes no3 according to rhf.

John3 · Jan 29, 2018

My alk will drop about 1 dkh per day without dosing. My calcium seems to hang around 410-440, so it could be dropping from the 440#. Should I be concerned if it drops from 440 to 410 between water changes?

Kershaw · Jan 29, 2018

John3 said:
My alk will drop about 1 dkh per day without dosing. My calcium seems to hang around 410-440, so it could be dropping from the 440#. Should I be concerned if it drops from 440 to 410 between water changes?

How is you coralline growth. I was dosing just ch because my tank was over run with coralline. It will put a large dent in ch before it affects the cal. My tank 125 at one point I only had 5 lps that where all about size of golf ball but had to raise ch 1 -1.5 dkh a day

Randy Holmes-Farley · Jan 29, 2018

Kershaw said:
It will put a large dent in ch before it affects the cal. My tank 125 at one point I only had 5 lps that where all about size of golf ball but had to raise ch 1 -1.5 dkh a day

Dent in what?

Kershaw · Jan 29, 2018

Dent in dkh of tank. The coralline seems to use allot. With out affecting the calcium. Water changes are able to maintain my calcium but not dkh

John3 · Jan 29, 2018

I have a lot of coralline that came on my live rock. Its basically maintaining, not spreading much but not dying. I don’t have any that grows on my glass or back wall. The tank and rock are now a little over a year old.

Kershaw · Jan 29, 2018

So not like this?

John3 · Jan 29, 2018

Nope nothing like that. It makes me wonder why I don’t?

Samina · Jan 29, 2018

Following along as the same goes for me. Ca maintains within a good range but Alk drops. And no real coralline growing, tanks over a year old as well. I do weekly water changes as well with Reef crystals. What exactly have you been dosing?

morgan175 · Jan 29, 2018

What’s your mag level?

jtvaughn · Jan 29, 2018

John3 said:
So I’ve read that most people dose ca and alk in a 2 part system. I’m using reef crystals for salt and I do weekly 20% water changes. My tank is 29g without counting the rock. It’s fairly stocked with corals at this point and everything is showing growth with some corals showing very good growth.

I find that my calcium barely drops over a week if at all but I find that I need to dose alk every day to keep it stable. Does that seem ok/normal? I find that if I don’t dose my alk drops about 1 per day.

Sure you can dose ALK daily if your CA2 is not dropping in the same proportions. Seems like the calcium levels in the crystals and the weekly water change schedule are keeping it in line. If you decide to start doing monthly water changes then it's time to start checking the calcium every week.

Samina · Jan 29, 2018

morgan175 said:
What’s your mag level?

Mine stays fairly high as well, like 1490-1500ppm.

John3 · Jan 29, 2018

Mag stays right around 1380-1400.

I dose Seachem Reef carbonate for alk. At one point I was dosing Seachem Reef complete but found my calcium was creeping up towards 500.

Randy Holmes-Farley · Jan 30, 2018

Kershaw said:
Dent in dkh of tank. The coralline seems to use allot. With out affecting the calcium. Water changes are able to maintain my calcium but not dkh

Well, for sure that isn't true. Coralline can only use calcium and alkalinity in a fixed ratio (about 18 ppm calcium for each 2.8 dKH in alk).

One issue is that many calcium kits cannot read the calcium precisely and accurately enough to see the decline properly. Salt mixes also sometimes have excessive calcium in them, which can make it harder to see the calcium decline when doing water changes,.

Randy Holmes-Farley · Jan 30, 2018

Just for folks asking, the magnesium level (whether low, high or perfect) is never a cause to deplete alkalinity and not calcium.

Randy Holmes-Farley · Jan 30, 2018

John3 said:
Mag stays right around 1380-1400.

I dose Seachem Reef carbonate for alk. At one point I was dosing Seachem Reef complete but found my calcium was creeping up towards 500.

I'm not a big fan of using unbalanced additives like these, but that aspect is not the cause of your calcium "issue".

What is the salinity and how are you measuring it?