Help with BRS 2-part dosing and stability

[reeferparty]

I'm fairly new to dosing but have done extensive reading on it prior to starting. I've been running BRS 2 part dose for about 3 months now but no matter what I do, I can't keep my parameters to stabilize.

~water volume 85g mixed reef

1.025 salinity
Temp 76-78
Ph 8-8.2
Alk 7.5-8.5 (Hanna)
Ca 400-420 (Red Sea)
Mg 1400-1600(nsw after WC with Fritz salt) (Red Sea)
No3 undetectable at the moment and working on raising back up to 5-10 (Red Sea)
Po4 .04-.08 (Hanna ULR)

Current dosing schedule is as follows:

Orange is Alk and blue is ca.

I've recalibrated my dosing pumps and took pumps off line for couple days to recalculate tank consumption -roughly 1.3dkh/day. However, despite dosing 78.9ml of equal parts over 24hrs, and rechecking at the same time every evening, I'm still getting about the same drop in Alk as if I didn't dose! Also, it seems as though my daily ca consumption is 20ppm. Is that too much? And it goes against the 20ppm per 2.8dkh rule of thumb. I feel that I'm already dosing a lot for what I have in the tank (little to no coralline algae). I do have minor precipitation on my glass down at sand level and a little in my return chamber where I dose.

I've been testing, recalculating, and tweaking constantly on a weekly basis but I can't seem to get things to fall in line. What should I do? Should I take doser off line and just dose by hand for a week to further confirm my tanks consumption? I'm absolutely stumped!! Thanks in advance

 

[reeferparty]

Sunday evening after WC Alk was at 8.6
Monday evening 7.6 -manually dosed up to 8.5
Tuesday evening 7.7 -manually dosed up to 8.5
Wednesday evening 7.4 -manually dosed up to 8.3

This is all while running my doser for 24hrs, dosing 78.9ml.

 

[Randy Holmes-Farley]

Did you calibrate the dosers? Many do not deliver exactly the specification.

How much was needed to reach those values when manually dosing? Did you measure the alk after the dosing, or is that a calculated value?

Remember, the higher the alkalinity, the higher the demand. So when you raise alkalinity, the demand to keep it stable increases.

 

[reeferparty]

Did you calibrate the dosers? Many do not deliver exactly the specification.

How much was needed to reach those values when manually dosing? Did you measure the alk after the dosing, or is that a calculated value?

Remember, the higher the alkalinity, the higher the demand. So when you raise alkalinity, the demand to keep it stable increases.

Yea, I calibrated my dosers. I manually dose 2oz to get back up to those values which were measured at least 15-30min after.

 

[Randy Holmes-Farley]

Yea, I calibrated my dosers. I manually dose 2oz to get back up to those values which were measured at least 15-30min after.

So it sounds like you just need to dose a bit more every day.

 

[reeferparty]

So it sounds like you just need to dose a bit more every day.

What I don't understand is that with my doser dialed in for my calculated daily consumption, why am I still being still having to manually dose for an additional 1dkh consumption?

 

[Randy Holmes-Farley]

What I don't understand is that with my doser dialed in for my calculated daily consumption, why am I still being still having to manually dose for an additional 1dkh consumption?

Incorrect calculations, apparently. How did you calculate?

 

[reeferparty]

I brought parameters to where I wanted them to be at, took doser offline for 2 days and tested at the same time every evening for the 2 days. I got 1.3dkh/day

 

[Randy Holmes-Farley]

I brought parameters to where I wanted them to be at, took doser offline for 2 days and tested at the same time every evening for the 2 days. I got 1.3dkh/day

As the alkalinity dropped so did the demand, leading to incorrect calculations of how much it takes.

It takes more each day to maintain 9 dKH than it does to maintain 7 dKH. That's why I'm not a fan of the calculation method (except perhaps as a starting point), but rather of trial and error dosing, adjusting to home in one the optimal dose.

 

[reeferparty]

As the alkalinity dropped so did the demand, leading to incorrect calculations of how much it takes.

It takes more each day to maintain 9 dKH than it does to maintain 7 dKH. That's why I'm not a fan of the calculation method (except perhaps as a starting point), but rather of trial and error dosing, adjusting to home in one the optimal dose.

Ok, so what do you recommend for my course of action? I'm currently at 78.9ml a day for an 85g mixed reef. I feel like I'm approaching the higher end, especially if I have to add another 60ml to compensate for the additional 1dkh

 

[Randy Holmes-Farley]

Ok, so what do you recommend for my course of action? I'm currently at 78.9ml a day for an 85g mixed reef. I feel like I'm approaching the higher end, especially if I have to add another 60ml to compensate for the additional 1dkh

If you used manual and auto dosing to get to a reasonable target, just put that all in the auto and see what happens.

 

[ncaldwell]

I'm having the same problem, I have my doser doing the same amount throughout the day and I have swings of up to 2 dkh between morning and night. Pulling my hair out but hopefully you get it figured out

 

[reeferparty]

If you used manual and auto dosing to get to a reasonable target, just put that all in the auto and see what happens.

Haha ok we'll see what happens! I just don't want to have precipitation