Dosing alk (soda ash)

[Acro maniac]

Here the thing i test with seachem ph/alk test kit. Alk tests at 5 drops which translates to 2.5 meq in my system. Makeup water also tests 2.5 meq (instant ocean). I have tested at this level since july previously stable at 3meq my concern is im bordering on the low side. Even though all looks well. I currently dosing 5 mil @3hrs brs 2 part alk and cal. I have manually dosed to raise the level to 3meq along with increasing autamated dosing only to stabilize back at 2.5 in 5 days .
I was wondering if something could be consuming or is that the happy level for my tank and shouldnt worry about it. Fwiw the tank has been running for 5-6years and 2 years ago had an alk swing i dont want to revisit. Also no precipitation anywhere.
Cal-425
Mag-1380
Ph-8.1-8.2
N- <5
Phos- undetectible,
All seachem except mag i use salifert.
Oh yeah system is about 100 gal total
And like i said earlier everything looks good now. More just trying to prevent a problem. Thanks

 

[Randy Holmes-Farley]

Instant Ocean will typically have a lot more alkalinity than 2.5 meq/L, More like 4 meq/L. So I'm worried your testing is not correct.

I would confirm the reading before adding anything.

 

[Acro maniac]

I do agree that in the past IO tested at 4 meq. I do remember that. It does seem as of lately the levels have changed. Could also be my test kits i will bring some water in the lfs to verify. Good reminder thank you.
Fwiw thelast box seemed a little higher on alk 3.5 -3 then this recent box which has tested at 3 - 2.5.
And calcuim has gone from 345-365 to 390-400 at 1.025 sg.
Just a realized the cal. Went up when i bumped up sg from 1.024 to 1.025, that makes sense but alk still went down. Will confirm tomorrow.

 

[Randy Holmes-Farley]

I do agree that in the past IO tested at 4 meq. I do remember that. It does seem as of lately the levels have changed. Could also be my test kits i will bring some water in the lfs to verify. Good reminder thank you.
.

I believe that unless you got a bad batch, that is a testing problem. I do not think the recipe changed.

 

[Acro maniac]

Test at the lfs has my level at 3 meq.
After observing their techniques of mixing i dont feel confident that is accurate either.
Im just going to purchase some new test and see for my self. As i said before tank still looks good so im not going to make any changes to dosing.
When making water for wc i have not changed the alk levels for IO i do bump up the cal and the mag and will continue the same practice. Hopefully the new test kits will gain my confidence back for the levels.

 

[Randy Holmes-Farley]

Sounds good.

Happy Reefing.

 

[Acro maniac]

Thanks i might revisit his again in the future

 

[Acro maniac]

Just a quick piece of info ..
I tested the reference alk sample and the level came 1 meq lower then the expected level.
Ordered new kits this morning

 

[Randy Holmes-Farley]

OK, sounds good.

 

[Acro maniac]

Just a heads up new salifert test came in last night. Test results were
3.02 meq. Back to normal for me. Thanks for the reminder to verify the test results. Sometime we skip the easy stuff and make things harder then they are.