Alkalinity Dropping Consistently

[AWildZacR]

Hi everyone, I've seen a few posts about this sort of thing but none have quite answered my issue.
My Redsea reefer 350 has been up and running just over 3 months now, and the alkalinity constantly drops despite my efforts!
I use redsea coral pro salt mix, and do a 10-15% water change every 2 weeks. The alkalinity of the water after mixing is always around 9.2.
Tank parameters:
6 fish & 25ish coral frags/small colonies (mostly LPS & softies)
1.025 salinity
0-5 nitrates
0 phosphates
470-500 calcium (slight fluctuations)
*alkalinity sticks around 7.1-7.4*
I dose redsea foundations for calc/alk via an auto doser, but have not began Mg dosing & testing yet.
I hardly dose any calc, 6ml/day, and have tried stopping that completely for a week with no change in alkalinity. I am currently dosing what seems like huge amounts(60+ml/day) of alk to maintain 7.1 in the tank and no luck raising it. API, hanna testers, and my LFS are getting the same low alk readings.
Please share any ideas about what the cause may be, and how I can fix my alkalinity(goal is ~8.6)! Thanks!

 

[LiveWire]

I would first measure my Mag and see if you need to make any adjustments there. I would also check my PH. You need those pieces of the puzzle.

 

[AWildZacR]

I would first measure my Mag and see if you need to make any adjustments there. I would also check my PH. You need those pieces of the puzzle.

My pH has been stable at 8.2, and my first mag test just showed 1265

 

[AWildZacR]

Update: Mg testing a bit high today (1390), and upon dosing 8.4 (ph & alk buffer) it condensed/precipitated in my display a little. Similar to when alk and calc reagents are mixed.

 

[jordan10]

Update: Mg testing a bit high today (1390), and upon dosing 8.4 (ph & alk buffer) it condensed/precipitated in my display a little. Similar to when alk and calc reagents are mixed.

How are u likeing the 8.4. I been using it my p.h stay at bout 8.0 and alk about 6.5. I trying the 8.4 but I don't seem to be raseing it like I like I guess. Just wanted know what u thought?

 

[AWildZacR]

How are u likeing the 8.4. I been using it my p.h stay at bout 8.0 and alk about 6.5. I trying the 8.4 but I don't seem to be raseing it like I like I guess. Just wanted know what u thought?

I used it much more on my smaller tanks (5-40gallons), and I loved it. Cant really overdose it, and it kept both ph and alk where I wanted. But on larger tanks like my 350 it doesn't seem to get the job done. I prefer more concentrated 2 part, especially with 8.4 precipitatating in my DT the way it has been.

 

[jordan10]

I used it much more on my smaller tanks (5-40gallons), and I loved it. Cant really overdose it, and it kept both ph and alk where I wanted. But on larger tanks like my 350 it doesn't seem to get the job done. I prefer more concentrated 2 part, especially with 8.4 precipitatating in my DT the way it has been.

so let's say I get my pH at eight 4 and my alkalinity still at a 7 can I keep dosing it without the pH going up anymore to get my alkalinity where I want it?

 

[FlowGod]

Hi everyone, I've seen a few posts about this sort of thing but none have quite answered my issue.
My Redsea reefer 350 has been up and running just over 3 months now, and the alkalinity constantly drops despite my efforts!
I use redsea coral pro salt mix, and do a 10-15% water change every 2 weeks. The alkalinity of the water after mixing is always around 9.2.
Tank parameters:
6 fish & 25ish coral frags/small colonies (mostly LPS & softies)
1.025 salinity
0-5 nitrates
0 phosphates
470-500 calcium (slight fluctuations)
*alkalinity sticks around 7.1-7.4*
I dose redsea foundations for calc/alk via an auto doser, but have not began Mg dosing & testing yet.
I hardly dose any calc, 6ml/day, and have tried stopping that completely for a week with no change in alkalinity. I am currently dosing what seems like huge amounts(60+ml/day) of alk to maintain 7.1 in the tank and no luck raising it. API, hanna testers, and my LFS are getting the same low alk readings.
Please share any ideas about what the cause may be, and how I can fix my alkalinity(goal is ~8.6)! Thanks!

What Corals do you have?

 

[AWildZacR]

so let's say I get my pH at eight 4 and my alkalinity still at a 7 can I keep dosing it without the pH going up anymore to get my alkalinity where I want it?

There are definitely people more qualified than me to answer that, hopefully they jump in, but in my experience it has never raised either above my acceptable range. I think the highest I've seen either ph or alk go with only 8.4 was 8.8.

 

[jordan10]

There are definitely people more qualified than me to answer that, hopefully they jump in, but in my experience it has never raised either above my acceptable range. I think the highest I've seen either ph or alk go with only 8.4 was 8.8.

Thanks me either I'll sit back and see I got a 65g. And I do 15ml and don't see much of a change just scared to do to much