Auto Dosing Times

AdamNC · Jul 5, 2015

Just recently started auto dosing , about 3-4 weeks ago. And got to thinking, when's the best times to dose Alk and Ca? I see some dose during the day and some dose at night, but no one has elaborated why one way or the other.

My schedule is as follow:
Alk at 8:00 am, 2:00 pm and 6:00 pm, 5 mins each dose, keeps me about 8.4-9dKh at test time
Ca at 9:00 am, 3:00 pm and 7:00 pm, 5 mins each dose, keeps me about 410-420ppm at test time

Normally I test about 5:00pm everyday but also wonder if the levels are dropping too much at night. I'm up at 5:30am tues-sat for work and sun-mon about 8:00am due to having a 2 1/2 yo son so late night testing is a bit out of the question. Would it benefit more to evenly space out the times at 8 hour increments or does my schedule look good?

saltyphish · Jul 5, 2015

cginter · Jul 5, 2015

I dose cal every hour and alk from 4pm-10am. Using apex and brs 1.1ml pumps

jasonandsarah · Jul 6, 2015

The main reason most people dose Alk at night is because it can help with the PH swing that happens at lights out. That leaves Cal to be dosed during the day because they shouldn't be dosed to close to each other.
I dose each 6 times per day on the hour and I start Alk at 10 pm, Cal at 10 am...

NanaReefer · Jul 6, 2015

I dose 2x daily of both. Morning 10 & 11am then 10 & 11pm. So far it's worked perfect with a stable ph of 8.2, ALK 9.0 and Ca 430

VJV · Jul 9, 2015

I dose 24 times per day calcium, Alk and Mag, with a 10min interval between each. The reason for this being we want our reefd to be as stable as possible.

jasonandsarah · Jul 9, 2015

VJV said:
I dose 24 times per day calcium, Alk and Mag, with a 10min interval between each. The reason for this being we want our reefd to be as stable as possible.

How much Mag can you dose daily and keep it stable?

VJV · Jul 9, 2015

To avoid stressing the corals you should avoid daily swings greater than 20ppm for Calcium, 10ppm for Mag and 1.4dKH for Alk. These are recomendations but i have seen people far exceeding them, especially in what concerns Mag. I dose the equivalent ammount that the tank consumes daily, spread over a 24h period to keep it as stable as possible.

VJV · Jul 9, 2015

Mind you, i use a dosing pump programmed to add the exact quantity each time. If i was doing it manually i would never be able to maintain such a schedule.

zemuss · Jul 9, 2015

I thought ALK and Calcium need to be dosed atleast 30 minutes apart?

Downbeach · Jul 9, 2015

I dosed Ca and Alk only, one on the hour, the other on the half hour every other hour, throughout the day. Bi weekly WC's kept my Mg ~ 1350ppm, so I never dosed it.

VJV · Jul 9, 2015

zemuss said:
I thought ALK and Calcium need to be dosed atleast 30 minutes apart?

Do not believe that is necessary. A number of commercially available two and three part solutions such as Red Sea or Fauna Marin tell you to wait 10 min between each. One thing I do recommend after trying both alternatives is to dose in the tank and not in the sump. This is open to much debate but after reading a lot about it and having personally tried both ways, I definitely prefer to dose the tank (Randy Holmes Farley is of the same opinion). The reasons for this are:

1- dosing in a small body of water such as the return pump chamber of the sump temporarily leads to over saturation and precipitation

2- it will quickly be sucked by the return pump and the contact with the warm parts of it also causes precipitation (not to mention ruined return pumps that calcified every 2-3 months)

3- ruined return pumps.

Dosing into a high flow area of your main display will avoid all this, and unless you are dumping a huge amount should not affect your livestock.

Just my two cents

bklynreef · Jul 10, 2015

Heres my 2 cents FWIW. I have 1000 gallons water volume and dose with a doser that spreads the interval times to separate each component at different intervals 24 hours a day to keep it stable. If I did this in the main tank and not in my sump I would have the corals blasted every time it dosed. If it works for you great but I know it wouldnt for me.
Cal 420
Alk 9.2
Mg 1420

Cal 500mg a day
Alk 800mg a day
Mag 2000 mg a day

Randy Holmes-Farley · Jul 10, 2015

The reason for a timing separation is that so the cloud of highly concentrated alk supplement and the calcium supplement do not interact and potentially cause excessive precipitation of calcium carbonate. Separating them may be done in time or in location in a larger system. How long to wait depends on the system and where you dose. A few minutes may be plenty long enough in a highly turbulent system without extended sumps and such.

Randy Holmes-Farley · Jul 10, 2015

jasonandsarah said:
How much Mag can you dose daily and keep it stable?

Not sure what you are asking, but magnesium depletes VERY slowly (0.1 to 2 ppm per day) and so infrequent dosing is fine for stability.

bklynreef · Jul 10, 2015

Jumping in here and just wondering why mag is the most used in my tank over all other parameters? If I dont dose high my cal and alk will drop or percpitate.
water changes 10 gallons daily which amonts to 300 gallons a month and the parameters are the same as the tanks parameters for stabilty.

jasonandsarah · Jul 10, 2015

Randy Holmes-Farley said:
Not sure what you are asking, but magnesium depletes VERY slowly (0.1 to 2 ppm per day) and so infrequent dosing is fine for stability.

I know it depletes very slowly and that's why I was asking the poster before me how he dosed it daily and kept it stable. I dose mag about every other water change.

Randy Holmes-Farley · Jul 10, 2015

jasonandsarah said:
I know it depletes very slowly and that's why I was asking the poster before me how he dosed it daily and kept it stable. I dose mag about every other water change.

Ah, well if you use a DIY two part, there's a specific ratio of magnesium to the other parts, and if you daily dose that amount in relation to the daily alk or calcium, it will remain stable. For my DIY recipe #1 (which is the more common recipe) it is about 1 mL of the magnesium additive for each 6 mL of the calcium or alk parts. So assuming you can dose that little, it can be added daily. However, dosing once a week is probably adequate for most people (dosing about the same amount used each day for calcium or alkalinity).

Randy Holmes-Farley · Jul 10, 2015

bklynreef said:
Jumping in here and just wondering why mag is the most used in my tank over all other parameters? If I dont dose high my cal and alk will drop or percpitate.
water changes 10 gallons daily which amonts to 300 gallons a month and the parameters are the same as the tanks parameters for stabilty.

Can you describe what you observe?
Rapid magnesium changes are either testing error (very common) or due to water changes. There's no process that allows magnesium to deplete much faster than about 1/10th of the calcium depletion rate.

bklynreef · Jul 10, 2015

If I dont dose high my mag will be at 1100 which is low and percipitates the other two values. This may be to the correct dosage while im bumping up the mag to keep it in the 1400's. Im hoping if it rises any more then ill start dropping the dosage. Could be the water changes as mag values are a bit lower at 1200.