Help with dosing 2 part and alk dropping

Lavey29 · Mar 8, 2022

Hi everyone, my tank is approaching a year old now and has quite a full stock of LPS and soft corals along with 12 SPS frags now and almost everything is thriving. The tank seems to finally have some balance. I keep my alk around 8.0 and was hand dosing 7.5ml of bionic alk daily. I now see that my alk has dropped to 7.4 over the past few days so I will have to increase my dosing to around 15 to 20ml maybe or more. I guess the corals and coraline are consuming more alk now and probably calcium also although that number doesn't seem to be dropping.

I know I need to get my doser operational but until then is it ok to hand dose 20ml or more into my sump as a one time a day dosage? Does it need to be spread out in smaller doses? Is it common to have different amounts of alk and calcium to dose or should they always be the same?

My DT is 65g and 15g sump so 80g volume. What is a normal amount of dosing for a tank this size with a full stock of corals?

Spare time · Mar 8, 2022

It might be handy to slowly drip the 20ml with a syringe into a powerhead or something. Are you seeing any precipitation when dosing?

Average alk consumption can vary dramatically between tanks

mdb_talon · Mar 8, 2022

I try not to have any single dose increase my alk by more than .5dkh. Not saying it is end of the world if you do but if that dose is enough to raise alk by more than a few tenths i would split it up personally. Even better set that doser up and do 4x5ml doses.

Generally alk and calc should be added equally and i always start with that until my numbers clearly show otherwise. Calc movement is less obvious because there is so much more of it in reef aquarium

Lavey29 · Mar 8, 2022

mdb_talon said:
I try not to have any single dose increase my alk by more than .5dkh. Not saying it is end of the world if you do but if that dose is enough to raise alk by more than a few tenths i would split it up personally. Even better set that doser up and do 4x5ml doses.

Generally alk and calc should be added equally and i always start with that until my numbers clearly show otherwise. Calc movement is less obvious because there is so much more of it in reef aquarium

How much alk do average size tanks with full load of coral typically consume?

Lavey29 · Mar 8, 2022

Spare time said:
It might be handy to slowly drip the 20ml with a syringe into a powerhead or something. Are you seeing any precipitation when dosing?

Average alk consumption can vary dramatically between tanks

I just split it into 3 doses in the sump. My alk consumption only showed a big increase this week. I'm assuming it's because I have a full load of corals now that appear to be growing combined with increase coraline growth.

vetteguy53081 · Mar 8, 2022

Watch your calcium levels and even reduce amount of doses of CA.
As beneficial as calcium can be for coral health and growth, there is a delicate balance that must be upheld in your aquarium. We have discussed in the past how almost every element in a reef aquarium is connected to another element. Changing one thing can lead to a ripple effect of consequences if you are new to the hobby.
In the case if calcium. . its connected with alkalinity levels. As calcium rises, alkalinity levels tend to drop. At the same time, an increase in alkalinity can decrease calcium. If your calcium levels are too high in your reef aquarium, you run the risk of your alkalinity is too low. The problem with this is that it affects the buffering capabilities of the water, which in turn affects the pH levels.

mdb_talon · Mar 8, 2022

I am not sure what the "average" is and it is easier to talk about using dkh rather than dosage because dosage is dependent on tank size and what specifically is dosed and how saturated it is.

I would guess an average for an established mixed reef tank may be around 1dkh daily...but thats just a pure guess based off what i see people talk about. In the past i have had tanks drop over 3 dkh daily if i didnt dose. My main ~220g frag system i got running now drops about 2.3dkh daily if i dont dose. I got another tank that is newer with mostly lps that would only drop about .5dkh daily without dosing.

Randy Holmes-Farley · Mar 9, 2022

Lavey29 said:
Hi everyone, my tank is approaching a year old now and has quite a full stock of LPS and soft corals along with 12 SPS frags now and almost everything is thriving. The tank seems to finally have some balance. I keep my alk around 8.0 and was hand dosing 7.5ml of bionic alk daily. I now see that my alk has dropped to 7.4 over the past few days so I will have to increase my dosing to around 15 to 20ml maybe or more. I guess the corals and coraline are consuming more alk now and probably calcium also although that number doesn't seem to be dropping.

I know I need to get my doser operational but until then is it ok to hand dose 20ml or more into my sump as a one time a day dosage? Does it need to be spread out in smaller doses? Is it common to have different amounts of alk and calcium to dose or should they always be the same?

My DT is 65g and 15g sump so 80g volume. What is a normal amount of dosing for a tank this size with a full stock of corals?

Hand dosing is fine, maybe twice a day.

20 mL of ESV B-ionic in your tank is only is about 0.5 dKH a day.

Lavey29 · Mar 9, 2022

vetteguy53081 said:
Watch your calcium levels and even reduce amount of doses of CA.
As beneficial as calcium can be for coral health and growth, there is a delicate balance that must be upheld in your aquarium. We have discussed in the past how almost every element in a reef aquarium is connected to another element. Changing one thing can lead to a ripple effect of consequences if you are new to the hobby.
In the case if calcium. . its connected with alkalinity levels. As calcium rises, alkalinity levels tend to drop. At the same time, an increase in alkalinity can decrease calcium. If your calcium levels are too high in your reef aquarium, you run the risk of your alkalinity is too low. The problem with this is that it affects the buffering capabilities of the water, which in turn affects the pH levels.

I do check calcium along with alk regularly and it has stayed pretty consistent at 470. The Hanna checker is not the easiest to use though as there was a big variation from my last ICP which showed cal at 384 and Hanna at 474.

Lavey29 · Mar 9, 2022

Randy Holmes-Farley said:
Hand dosing is fine, maybe twice a day.

20 mL of ESV B-ionic in your tank is only is about 0.5 dKH a day.

That seems to be close to what I am using up in the tank on a daily basis now.

How much variation is there typically between daytime and night time alk numbers?

Is it better to dose in the peak day time or evening?

arking_mark · Mar 9, 2022

vetteguy53081 said:
Watch your calcium levels and even reduce amount of doses of CA.
As beneficial as calcium can be for coral health and growth, there is a delicate balance that must be upheld in your aquarium. We have discussed in the past how almost every element in a reef aquarium is connected to another element. Changing one thing can lead to a ripple effect of consequences if you are new to the hobby.
In the case if calcium. . its connected with alkalinity levels. As calcium rises, alkalinity levels tend to drop. At the same time, an increase in alkalinity can decrease calcium. If your calcium levels are too high in your reef aquarium, you run the risk of your alkalinity is too low. The problem with this is that it affects the buffering capabilities of the water, which in turn affects the pH levels.

@Randy Holmes-Farley Can you provide the chemistry behind this?

Randy Holmes-Farley · Mar 9, 2022

Lavey29 said:
That seems to be close to what I am using up in the tank on a daily basis now.

How much variation is there typically between daytime and night time alk numbers?

Is it better to dose in the peak day time or evening?

Alk most often declines only (never rises), and it declines mostly during the day. Dosing through the day leads to alk stability. Dosing high pH alk supplements at night leads to more pH stability.

mdb_talon · Mar 9, 2022

arking_mark said:
@Randy Holmes-Farley Can you provide the chemistry behind this?

FYI if you want the full article he copied it from it is here: https://reeftankresource.com/reef-tank-calcium-level/

Randy Holmes-Farley · Mar 9, 2022

arking_mark said:
@Randy Holmes-Farley Can you provide the chemistry behind this?

I think the connection is fairly weak, and I'd generally ignore it for most purposes, but it is real and driven mostly by abiotic precipitation. Calcium doesn't generally drive faster biological calcification at any level.

The tendency to precipitate is directly driven by the multiplication product of the calcium concentration times the carbonate concentration.

The biggest driver is pH (higher pH drives bicarbonate to carbonate). A difference of 0.3 pH units (say, 7.9 to 8.2) is a factor of 2 in carbonate. A difference of 0.6 pH units (7.8 to 8.4) is a difference of about a factor of 4 in carbonate concentration.

Second biggest driver is alk, because alk can range over a factor of 2 between the lowest reefers have and the highest (say, 6 to 12 dKH).

Calcium is a weak driver since it rarely varies much out of the 350-550 ppm range, so is less than a factor of 2.