How fast can CAL and ALK demand increase??

[LoJack]

Hey guys,

Just curious about something ... I set my 2 part dosing up a while back and for the most part, the demand has stayed rather stable.

I hadn't even tested in a few weeks because everything was doing so great. But I've noticed a slow down in growth so I checked it today.

ALK 6.5
CAL 400
MAG 1400

in 3 weeks can the demand really go up that much? I've never noticed large swings. I'm currently adding about 100 ml each of calcium and alkalinity per day and it was maintaining my levels spot on.

I guess it just seems like the levels have fallen too far too fast for the tank to need that much more solution daily

Any thoughts?

[toothman]

gfo can lower kh

[Allmost]

as corals grow more they take up more Alk and CA.

that is why you need to test it at least weekly when things are good.

now this is going to set you back 3 weeks unfortunetly.

[LoJack]

gfo can lower kh

I wasn't aware of that

as corals grow more they take up more Alk and CA.

that is why you need to test it at least weekly when things are good.

now this is going to set you back 3 weeks unfortunetly.

Yup ... definitely going to set me back. I'm just glad the swing hasn't had any negative affects other than growth. I'm not worried about setting myself back as long as my corals health isn't affected.

Looks like I'll be going through a whole lot more 2 part in the future ... time to place another big order haha

[AdamDeMamp]

In five months my parameters dropped from ca 450 to 370 and kH 8 to 6.4 using brs 2 part via dosing pumps and io salt. I did have a lot of growth in my sps with no color loss and great pe. I've since slowly been adding a few minutes to the timers to bring the levels back up.

[LoJack]

I also use BRS two part and IO salt. I'm just surprised at how fast the demand increased.

I figured it might be a bit on the low side, but an ALK drop of 1.5 dkh on a balanced tank and a CAL drop of 40 ... just seemed high to me.

I'll try and get it all rectified and get it back on track. Looks like i'm on pace to start going through a whole lot more two part though.

[Irsug1]

Question - BRS 2 part doser. Do you all dose equal parts Cal & Alk or do you dose the appropriate amount of each to hold a specific level? Thanks

[LoJack]

Right now I dose equal parts of each. However if I notice a change in demand I'm setup to dose more of one than the other. They are just simple timers controlling them.

[jroovers]

That seems like a pretty fast drop over that time span, could other factors such as a larger water change or two, or new batch of salt enter in the equation as well? I typically have had to bump my dosing of 2-part in the vicinity of 5 to 10 mls per day every 6 months or so. Opposite to you, I find my alk is usually always near ideal (7.5 - 8) and my Ca is the one that is always low (recently as low as 325, and ideally I'm trying to run in the 420 area). I just bump it back up with some manually dosing and jack up the dosers a bit and away you go. I don't think that at those parameters you should se any negative effects, but alk below 7 starts to get me a bit concerned.

[animalkingdom]

That seems like a pretty fast drop over that time span, could other factors such as a larger water change or two, or new batch of salt enter in the equation as well? I typically have had to bump my dosing of 2-part in the vicinity of 5 to 10 mls per day every 6 months or so. Opposite to you, I find my alk is usually always near ideal (7.5 - 8) and my Ca is the one that is always low (recently as low as 325, and ideally I'm trying to run in the 420 area). I just bump it back up with some manually dosing and jack up the dosers a bit and away you go. I don't think that at those parameters you should se any negative effects, but alk below 7 starts to get me a bit concerned.

+1 to this. I'd check for precipitation in the area of the sump you are dosing. If the two part is not mixed well when entering the tank precipitation is more likely. Good thing you caught that it was low soon. I find prolonged periods in the 6's lead to STN a few months later.

[MHG]

You call that fast? My 60 cube was consuming 16ml of alk a day for a year and a half. I changed the flow on my two MP10 pumps from a short anti sync pulse to a 5 second long anti sync pulse and in 3 days my alk consumption went to 25 ml a day. It has been there for about 6 months...Growth has never been better...

[Touring]

You call that fast? My 60 cube was consuming 16ml of alk a day for a year and a half. I changed the flow on my two MP10 pumps from a short anti sync pulse to a 5 second long anti sync pulse and in 3 days my alk consumption went to 25 ml a day. It has been there for about 6 months...Growth has never been better...

that's interesting and cool

[LoJack]

+1 to this. I'd check for precipitation in the area of the sump you are dosing. If the two part is not mixed well when entering the tank precipitation is more likely. Good thing you caught that it was low soon. I find prolonged periods in the 6's lead to STN a few months later.

No precipitation. I have a powerhead right where I dose specifically to make sure that I have good mixing.

Also, precipate usually forms due to oversaturation doesn't it? I have the opposite problem lol.

I increased the dosing by 30 minutes a day and it has balanced everything out for now. I'm thinking that maybe consumption did just go up. More SPS than I've ever had, and some pretty substantial growth on some of them. That calcium has to be coming from somewhere I suppose

[jroovers]

No precipitation. I have a powerhead right where I dose specifically to make sure that I have good mixing.

Also, precipate usually forms due to oversaturation doesn't it? I have the opposite problem lol.

I increased the dosing by 30 minutes a day and it has balanced everything out for now. I'm thinking that maybe consumption did just go up. More SPS than I've ever had, and some pretty substantial growth on some of them. That calcium has to be coming from somewhere I suppose

It is possible your consumption did go up. Remember there are a lot of variables at play. How accurate are your test results? How accurate is your measure when mixing Ca and Alk solution? How often do you do water changes and what salt do you use (what is their Alk and Ca values)? What is your Mg level and how accurate is that test (if too low it can cause the Ca to come out of solution). So in the end, things may have not changed as much as you think, but it could be a combo of various factors. If you are seeing growth, it could be demand has gone up slightly, and your test results are a bit skewed/within the source of error and just make it look a bit more drastic than it really is. If everything is growing and colourful, nothing to worry about. I would re-test that alk though a couple of times in the next week or two to make sure it is indeed above 7.