ALK drop, why?

[Randy Holmes-Farley Verified Community Expert]

Sooo let me get this straight... I may sound dumb here. Let's say I'm currently giving my tank 35ml a day of alk, your saying that I should also dose my tank with 35ml of cal?

That is the best way to use a two part system, otherwise, there's no advantage of a two part over totally independent dosing of calcium and alkalinity.

Calcium should not rise in this scenario, except as a water change keeps boosting it if you start with a high calcium mix.

OTOH, if calcium actually gets too high for some reason, stopping the calcium dosing is fine. The two part might be mismade, or there might be some other issue going on.

 

[Randy Holmes-Farley Verified Community Expert]

I'm also experiencing a depletion of alk pretty rapidly. About .5 dkh/day and calcium stays around 420-430 so felt there wasn't a need to dose cal.

Sorry didn't mean to hijack your thread.

Some salt mixes have so much excessive calcium in them that it can maintain calcium bu water changes. But the two part should only offset the demand in the tank (if properly made). With equal parts of two part dosing, calcium might end up a bit higher, but it won't keep going up and up.

You need to monitor calcium over a long period to actually see a decline. 0.5 dKH can be detected with a kit, but the calcium decline expected with that alk decline is only about 6 ppm, which is unnoticeable with most kits. It might take 3-5 days to really see that decline with many calcium kits. Then once you see a 20-30 ppm decline in calcium, you end up adding a bunch of days worth of calcium to get back where you were.

 

[Randy Holmes-Farley Verified Community Expert]

My LFS will not use IO, they say it's only good for crashing tanks

Maybe they make less profit margin on it.

FWIW, aside from one bucket of Seachem salt 19 years ago, and 3 buckets of Reef Crystals ordered by accident, I've used nothing but IO for 19 years and my tank never crashed due to salt.

 

[NanaReefer]

Personally if it wasn't for my Birds Nest's slow decline I wouldn't be dosing. All other corals are doing wonderful! Tank is crystal clear, no nuisance algae growth and my fish & inverts are thriving.
I feel I'm the one who caused the issue in the first place. Tested my Alk and it read 6.7 so I panicked! Even though it had great PE at the time, it was lacking color. I'm thinking it was due to the low Alk. So I start dosing. Now it has several branches showing very little to no PE at all My first SPS to keep alive longer then 2wks and I wind up killing it

 

[Randy Holmes-Farley Verified Community Expert]

IMO, 6.7 dKH is not a panic, just a sign to dose a bit. The ocean actually runs about that level.

 

[NanaReefer]

IMO, 6.7 dKH is not a panic, just a sign to dose a bit. The ocean actually runs about that level.

Now he tells me!! <sigh> Story of my life-lol

 

[Randy Holmes-Farley Verified Community Expert]

Sorry...

Good luck going forward!

 

[NanaReefer]

Sorry...

Good luck going forward!

I was only kidding Randy

 

[Randy Holmes-Farley Verified Community Expert]

I know.

Happy Reefing.

 

[NanaReefer]

I am very pleased to report that all parameters have been very steady at....
ALK=8.4
CA=430
PH=8.0 @8a.m
Temp=77.9
SG=1.026

I am dosing 20ml of BRS 2part.
Equal amounts of each.
10ml 2x daily. 2hrs apart from each other.
At 12hr intervals.

Thank you again Randy

 

[Randy Holmes-Farley Verified Community Expert]

That looks good.

Good luck and happy reefing.

 

[NanaReefer]

Well ***? Tested this morning before dosing and Alk has risen to 8.7-8.8 Been dosing same time/amount. I don't get it!
It's time for a WC so now what do I do?

 

[Randy Holmes-Farley Verified Community Expert]

My first bit of advice is to not stress over the difference between 8.4 dKH taht you were happy with and the actual 8.7-8.8 dKH today! That is a small difference.

Just downward adjust the dosing a bit (not too much) to let it decline again.

 

[NanaReefer]

I was dosing 20ml daily. Would 18ml be ok?
See if I had any inkling at all about chemistry, I most likely wouldn't panic-lol. But if you say this rise is minor, thats good enough for me.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, it is minor.

18 mL per day sounds fine to try for a few days. Don't over-interpret small difference that might just be testing variation.

 

[NanaReefer]

After 2 full days dosing 18ml a day my Alk is now at 9.2. Should I continue at 18ml or drop it even more. I know 9.2 is acceptable, I'm just concerned about the steady rise affecting my corals. Or no doses today and see if there's any drop by tomorrow?

 

[zemuss]

IMO continue to drop the dosing to 15ml and again until your testing is consistent. 9.2 isn't bad but if it took 2 full days to reach that number than 15Ml might do the trick.

 

[Randy Holmes-Farley Verified Community Expert]

I agree I'd drop it a bit again.

 

[zemuss]

I would also track this changes in Excel if I were you. Try to graph the data too. I believe you started at 8.4 and the alk increased to 9.2 in X number of days. This is much better than it going to 9.2 in 10 minutes.

Now slowly adjust to 15mil per solution and it should start coming back to 8.4 once it levels all this is the maintenance dose.

I hope this works for you. If you need help with excell i can lend a hand.

 

[NanaReefer]

Thanks guys I'm on it!