Alkalinity consumption

[SuncrestReef]

My SPS corals have been going through a nice growth spurt over the past month. My alkalinity consumption has been increasing, so I've been increasing the amount of BRS 2-part dosed each day spread out evenly over a 24 hour period. I'm now dosing 100 ml per day on my Reefer XL 425 (approx 107 gallon total system volume). According to the BRS dosing calculator, that equals about 1.3 dKH per day of consumption.

For you more experienced reefers out there, is this normal or does it seem unusually high?

Here you can see some of the new growth tips:







Even my green slimer (which was at death's door just a couple months ago) has bounced back nicely:

 

[laverda]

That does not seem high at all. It really depends on how many corals and there size. I had a 29 gallon with SPS and a large clam I used to dose 50 ml a day.

 

[SuncrestReef]

That does not seem high at all. It really depends on how many corals and there size. I had a 29 gallon with SPS and a large clam I used to dose 50 ml a day.

I have about 70 SPS and LPS corals, ranging in size from 1" frags up to colonies the size of a softball, and about a dozen softies.

Thanks for your input. 50 ml on a 29 gal is a lot more than my ratio.

 

[laverda]

The clam used a lot of it in my tank. It grew from 3” to almost 12” while in that tank.

 

[Vahanyos]

Judging from all the coraline and you’re fast coral growth, it seems normal to me.

I only have a 42g, and keep my alk stable at 8. I started dosing 6ml a day 2 months or so ago, and when my coraline and sps started taking off I had to increase it quick. Im at 16ml a day now but I’m noticing my alk dropping slowly as well. .1 increments but it’s happening fairly quickly. If I had colonies your size I would probably be doing higher than 16ml a day so reading your post doesn’t raise any concern to me

 

[Randy Holmes-Farley]

Normal alk consumption is 0.5 to 4 dKH per day. Even a soft coral tank can use 2 dKH per day.

 

[SuncrestReef]

Normal alk consumption is 0.5 to 4 dKH per day. Even a soft coral tank can use 2 dKH per day.

Great! I had done some searching but couldn't find any basic guidelines like this. Thanks for this info.

 

[Randy Holmes-Farley]

Some folks, of course, can have even less, but that implies little coralline or hard coral growth. new tank, or just one without much of those growing. 1-2 dKH per day is most common.

 

[DarkReefer]

Just found this thread after a search. I used to be able to dose about 7.5ml of Coral Essentials Carbonate + Trace and it would bump my alk by about .5dKH (Tank is a Waterbox 70.2).
I've been having some nutrient swings over the past several months and most recently the alk seems to be dropping quite a bit. I've also just set up a Kamoer X4 Pro doser and over the past 3 days have been gradually increasing the daily doseage (done over 8 doses throughout a 24hr period).

Initially I set it up with about 15ml as I need to bump it up at the moment rather than maintain and was looking to bring it up 1dKH a day. After day 1 I tested and there was no movement, so I raised it to 20ml. Tested day 2 and it was showing it'd moved from 5.6 to 5.8.
I've now bumped it to 30ml for remainder tonight/tomorrow (again, dumping 8 separate times so only about 3.8ml each time) and I'll test again around the same time and see where we're at there. Hopefully it'll start steadily climbing and once I get it to the right levels (aiming for 9), I'll wind it back to try and maintain.

I guess I'm just surprised having to dose so much in the 24hr period when up until a couple months back it was fine with .5 bumps with only 7.5ml. Though the new dosing unit, even though I've tried to calibrate it, I don't believe it to be exactly accurate, but as long as I work it out and work around it's nuances it'll be fine. Can't wait to find the stability!

 

[homer1475]

Just found this thread after a search. I used to be able to dose about 7.5ml of Coral Essentials Carbonate + Trace and it would bump my alk by about .5dKH (Tank is a Waterbox 70.2).
I've been having some nutrient swings over the past several months and most recently the alk seems to be dropping quite a bit. I've also just set up a Kamoer X4 Pro doser and over the past 3 days have been gradually increasing the daily doseage (done over 8 doses throughout a 24hr period).

Initially I set it up with about 15ml as I need to bump it up at the moment rather than maintain and was looking to bring it up 1dKH a day. After day 1 I tested and there was no movement, so I raised it to 20ml. Tested day 2 and it was showing it'd moved from 5.6 to 5.8.
I've now bumped it to 30ml for remainder tonight/tomorrow (again, dumping 8 separate times so only about 3.8ml each time) and I'll test again around the same time and see where we're at there. Hopefully it'll start steadily climbing and once I get it to the right levels (aiming for 9), I'll wind it back to try and maintain.

I guess I'm just surprised having to dose so much in the 24hr period when up until a couple months back it was fine with .5 bumps with only 7.5ml. Though the new dosing unit, even though I've tried to calibrate it, I don't believe it to be exactly accurate, but as long as I work it out and work around it's nuances it'll be fine. Can't wait to find the stability!

Why wouldn't you do a one time BOLUS dosing to get it to where you want, then figure out he daily dosing from there? You know go from 8 to 9 in one shot, then maintain from there.

Seems counter productive to just keep bumping the daily dose a little bit every day, and could easily overshoot.

 

[DarkReefer]

Why wouldn't you do a one time BOLUS dosing to get it to where you want, then figure out he daily dosing from there? You know go from 8 to 9 in one shot, then maintain from there.

Seems counter productive to just keep bumping the daily dose a little bit every day, and could easily overshoot.

Current alk level is 5.8, so there's quite a jump to get it to 9 and I wouldn't want to bump it that much in one hit. Some corals etc in the tank are a bit rough after the past couple months of having phosphate increases and nutrients all a bit messy and unstable so I'm trying to increase without stressing too much.
Looking to increase by about 1dKH a day, which should be easy enough to find by adjusting my daily dosing to find the sweet spot, and then adjusting down again once it gets closer to where needed.

 

[homer1475]

yeah from 5.8 to 9 is a huge jump, agreed. I thought I was reading from 7 to 8, then from 8 to 9, sorry I misunderstood.

If it were me, I would BOLUS dose from 5.8 to 7 to get into a "safe range", then try to adjust up from there. Then the same time daily go up 1 DKH point a dose till you hit your 9, then figure out daily consumption from there.

Much easier to figure it out that way, then trying to bump up the dosage to get to your level, then reduce it every day to figure out daily consumption.

Might also want to do the BOLUS dosing with something like plain old arm and hammer baking soda(Google Randy's DIY 2 part). Much easier and cheaper then a premade product.

 

[Randy Holmes-Farley]

Do you detect any signs of calcium carbonate precipitation, such as hardening sand?

 

[DarkReefer]

Do you detect any signs of calcium carbonate precipitation, such as hardening sand?

None that I'm aware of, all the sand still seems to be as per normal that I've noticed.

 

[Randy Holmes-Farley]

None that I'm aware of, all the sand still seems to be as per normal that I've noticed.

Then assuming you have confidence that the kit value is correct, I'd slowly raise it with baking soda (not washing soda or most reef alk supplements). You don't want to boost the pH appreciably in case precipitation is the issue.

 

[DarkReefer]

Then assuming you have confidence that the kit value is correct, I'd slowly raise it with baking soda (not washing soda or most reef alk supplements). You don't want to boost the pH appreciably in case precipitation is the issue.

Thanks for the advice Randy.
Tested again today and it's again only gone up .2 dKH so now sits at 6.0 after dosing 30ml over the past 24hrs.

I've increased the dose to 40ml now.
Regarding the kit, I've not had issue previously, though I've wondered whether it perhaps needs a battery change (less than 12months old Hanna tester). From what I can see based on colour of the sample though it seems a little light and not as blue as it should be when it gets around the 8dKH mark.

 

[DarkReefer]

Welp, looks like I've had an oopsie with the dosing.

So after the above with the daily testing things seems to be on track and creeping slowly, there were a few days where it seemed to start going backwards again so I upped the dosage slightly again. This past 5 days has been pretty nuts with various things going on so haven't been able to or motivated to do my testing until today.

Today's reading was off the chart at 14.4!
I've wound the dosing back by approximately half on the kamoer app, but I've switched off that pump for the moment.

I was going to do a WC today but I'm thinking I'll just leave the tank as is and let it use up the alk itself over the next 4 days as I need to go away for a short bit. Thinking by the time I get back it should be around where it needs to be and then I can monitor and turn the doser back on based on a days usage etc.

Funnily enough my Phos has dropped right down to 0.031 (was previously at 0.258 5 days ago). Everything else seems somewhat close-ish to where it needs to be (Cal needs a slight bump at 365 after being 380 5 days ago) and Mag dropped to 1320 (down from 1455 5 days ago).
Pump turned back on for the mag and cal dosage increased slightly also.

 

[Randy Holmes-Farley]

Today's reading was off the chart at 14.4!

Any chance the previous readings were in error?

 

[DarkReefer]

Any chance the previous readings were in error?

I'm not too sure but I don't think so, colour wise this test was VERY blue in colour once the reagent was added, unlike previous tests which were more of a yellow/greenish colour (typical to that of a low Alk reading).

 

[Randy Holmes-Farley]

I'm not too sure but I don't think so, colour wise this test was VERY blue in colour once the reagent was added, unlike previous tests which were more of a yellow/greenish colour (typical to that of a low Alk reading).

You are using the Hanna alk checker? Just asking because that color description doesn't sound right for a normal alkalinity titration.

In any cause, I'm not sure why its much higher now unless something happened to slow consumption in the tank.