Alkalinity HELP

[Mike Lemming]

Hey everyone, I have a loaded question with a few moving parts that I was hoping someone could give me an advice or clarity to what the heck is going on in my tank!

I have a standard 125 with a Ruby 36 sump for a total of a 130g (roughly) total system volume. It's been running for about a year, but half of the rock has been in water for over 2 years. The tank is lightly stocked with only a handful of corals with minimal Cal/Alk demand. I am running Kalk in hopes to raise ph and a refugium on a reverse light cycle.
My alkalinity seems to be depleting rather quickly for the amount (or lack there of) of coral with Cal/Alk demand. I tested on Tuesday night with a Hanna checker and got a 7.9 reading. I dosed 90ml of alkalinity to bring it to 8.5 based on the BRS calculator. I again tested Wednesday night around the same time for a reading of 7.6. It went down?! Checked yet again Thursday night for a reading of 6.9 and dosed the 90ml again (not trying to raise the Alk any more than 1dkh in on dose). Hanna checker has new batteries and reagent was just purchased and doesn't expire until 2025/2026.

I noticed my sand binding together a few weeks ago but have since gotten my hands in there and went around the entire tank to break up the chunks. I have also had a decent amount of coralline growth (lots of small spots starting). Clean up crew is rather minimal with only about 15 snails, maybe 6 or 8 crabs and one peppermint shrimp for aptasia control.

Also, I tried switching to All For Reef thinking that my BRS alk mix may be bad or something, but my mag and cal has gone up but alk still low.

Rock structure is NSA if the bonding between rocks(low viscosity super glue and sand) may effect anything. (Pic below in comments)

As of yesterday
Cal: 510
Mag: 1320
Alk: 6.9
Salinity: 1.026
Temp: 77-78

Does anyone have a clue as to why my tank would be consuming so much alkalinity with such minimal demand? I'm at a loss..

Feel free to ask away if I have missed anything.

Thanks for any and all help/advice!

 

[Mike Lemming]

 

[JohnK]

Are you seeing coralline growth increasing by chance?

I've never used AFR, but keep in mind that there is some process involved and IIRC the alk takes a while to show/test after it's added. Thinking that could confuse things a bit.

 

[Mike Lemming]

Are you seeing coralline growth increasing by chance?

I've never used AFR, but keep in mind that there is some process involved and IIRC the alk takes a while to show/test after it's added. Thinking that could confuse things a bit.

I have a bunch of coralline starting but they're all little spots. like the size of a pea. I dosed All For Reef for like 10 days, watching my calcium and magnesium going up but my alk going down. I figure 10 days was enough for the alkalinity to show itself right?

 

[MichaelJ]

Every time I use AFR. it takes a day or two to get real readings…for my rank that is…. Usually on the 3rd day….I now only use it when I run out of other stuff….other people may have different outcome of course.

 

[JohnK]

Huh, I don’t know about the AFR? Coralline is known for really sucking up alk when it get growing.

 

[Mike Lemming]

Every time I use AFR. it takes a day or two to get real readings…for my rank that is…. Usually on the 3rd day….I now only use it when I run out of other stuff….other people may have different outcome of course.

That's what I thought. My alk continued to lower even after like a week. I'm stumped.

 

[MichaelJ]

That's what I thought. My alk continued to lower even after like a week. I'm stumped.

Bad bottle of AFR? I’d go get Red Sea or something and can the AFR.

 

[JohnK]

Curious though, that Ca number is pretty high. Perhaps there is more than a little precipitation happening?
I might try stopping the AFR, and only adding alk until the Ca comes down a bit. Then restart AFR.

 

[MichaelJ]

Curious though, that Ca number is pretty high. Perhaps there is more than a little precipitation happening?
I might try stopping the AFR, and only adding alk until the Ca comes down a bit. Then restart AFR.

Would that contribute to the lowering of the Alk?

 

[Mike Lemming]

Curious though, that Ca number is pretty high. Perhaps there is more than a little precipitation happening?
I might try stopping the AFR, and only adding alk until the Ca comes down a bit. Then restart AFR.

That's what I've done. Dosing BRS Alk only and testing. Calcium is slowly coming down. It was like 550 on a week ago.. I may even stop the kalk to see what happens..

 

[JohnK]

Oh yes skip the kalk too. No “balanced” additives until things fall back into balance .

 

[JohnK]

Would that contribute to the lowering of the Alk?

Anthony Calfo had this analogy, a gross oversimplification i’m sure, but it illustrates the point.

You have a bowl that holds 100 marbles. Half red, half white. Add more marbles and the bowl overflows.
The Ca and alk basically just sticking to each other and falling out of solution in that balanced ratio (that AFR, and kalk, both provide). Equal parts dosed, equal parts precipitating.
Ca stays high, alk stays low, like it’s stuck.

Randy H-F has an article to actually explain. I’ll link it later if someone else doesn’t beat me to it.

 

[MichaelJ]

Anthony Calfo had this analogy, a gross oversimplification i’m sure, but it illustrates the point.

You have a bowl that holds 100 marbles. Half red, half white. Add more marbles and the bowl overflows.
The Ca and alk basically just sticking to each other and falling out of solution in that balanced ratio (that AFR, and kalk, both provide). Equal parts dosed, equal parts precipitating.
Ca stays high, alk stays low, like it’s stuck.

Randy H-F has an article to actually explain. I’ll link it later if someone else doesn’t beat me to it.

Ok, this’ll be interesting thread to watch….thanks

 

[JohnK]

I probably explained horribly, but the answers should be in here;

Chemistry And The Aquarium: Solving Calcium And Alkalinity Problems

I hope this article proves useful is understanding and dealing with the different types of calcium and alkalinity problems encountered by reef keepers. Once you get calcium and alkalinity under control, you are far along the road to having your tank chemistry optimal for its inhabitants.

reefs.com

Looks like we are talking about zone 4.

 

[dz6t]

I personally do not use nor recommend AFR:
AFR is calcium formate
1. In saltwater environments, some bacteria will convert formate part of AFR to formaldehyde, which is dangerous to animals even in trace amount.
2. The mechanism of AFR to add alkalinity is:
Bacteria slowly (can be from hours to a day) convert formate into carbon dioxide, yes, that is right, it generates “carbon dioxide” inside the tank then is converted to bicarbonate to suppliment alkalinity. Basically like bubbling carbon dioxide inside the tank. Well, it can lower the pH.
I saw a guy use AFR along with a CO2 scrubber, which is very unfortunate.

3. You can’t use alkalinity test to guide your dosing as AFR add alkalinity slower which adding calcium immediately.

 

[JohnK]

Please note, ^ He's a chemist, I'm not

 

[PSU4ME]

I would do some water changes to try and better balance the Alk and Ca. Your sand binding tells me that something is precipitating out (alk)

 

[dz6t]

By the way, in general, corals consumes more alkalinity than calcium. The reason is that coral utilizes alkalinity as a carbon source for growing its flesh as well as other organic matters. Only part of alkalinity that coral takes in is used for building skeleton.
So the thought of 1:1 ratio of dosing alk and calcium is outdated. But the good thing is that coral is not very sensitive to calcium level, anywhere from 300 to 500 ppm of calcium makes not much difference.

 

[coralfishreef]

It can be difficult to use AFR. It’s dependent on bacteria and the delayed consumption and conversion makes it more difficult to test Alk, Calc. I tried AFR, but went back to 2-part. It’s okay to use with a soft coral tank, but easier to create spikes which is not great for an SPS tank.

Instead of 2 or 3 dosing methods, go with 1, either kalk, or 2 part. For raising pH, an outside airline to the skimmer intake is the easiest method that I’ve found.

Marbles

The Right Way to Use 2-Part Additives

Nearly 20 years ago a company called E.S.V invented a product called B-ionic. This was a product that came in two bottles that replenished both calcium and alkalinity in their natural, ionic balanc…

joejaworski.wordpress.com