I Give Up. Help Alk Dropping No Matter What I Do

[mcola78]

I am at a loss here and hoping you all can help out. I have been in this hobby for almost 30 years and never had a hard time keeping mixed reef tanks. My current tank is actually doing very well being only 8 months old but I cannot for the life of me maintain ALK and CA using the current Apex DOS. Any ideas what is going on?

Tank: 150 gallons. Sump 30 gallons. Minus rock, estimate 165 gallons of water. I run 4 radions and a custom sump with UV, Reeflife Protein Skimmer, Apex DOS and Trident
Using Bulk Reef Two Part Soda Ash & Calcium Chloride at 2.5 cups per gallon into a 5 gallon dosing container. Currently dosing 200ml of each over 24 hours with a 7-minute gap between each. Both DOS and Trident have been recently calibrated. I also have some Chaeto in a small section of the sump

Current Measurements:
Temp 77.2
PH 8.54
ALK 5.98 (trying for 9.5)
CA 411 (trying for 450)
MG 1425
Ammonia 0
Nitrite 0
Nitrate <1
Phosphate 0.08

I am trying to get ALK to 9.5 and CA to 450. I CAN get these to this level short term using multiple options like one-time large dose or WC, it just never stays at it. Before I added a ton of sps frags, I was dosing 60ml of each over a span of 24 hours and this was working. When I added about 20 sps and live rock with coralline algae, this all changed. ALK and CA dropped more rapidly and I have tried everything to maintain with ZERO success.

In 24 hours, if I stop dosing, ALK drops 1.29. Recent test dropped from 7.27 to 5.98. CA drops from 416 to 411. To fix ALK, the calculator would show that I should dose 165 ml of the above to move levels back to 7.27. When I do this dose of ALK over 30 minutes and retest, level jumps back up to 7.64--so the calculator levels seem about right.

Unfortunately, using the 24-hour set periods in Apex have resulted in drops of ALK and CA no matter what. I have changed these daily levels from 165ml to 300ml with drops no matter what. I am not seeing any precipitation on the pumps and my sand is not clumping.

I have done a large water change to reset and that works, but the levels just drop again. I have changed dosing amounts, I dose in a high flow area in the sump right by the return pump but nothing is working.

I am assuming I just need to so something different on the DOS times but looking for advice first. I am lost and losing my mind. Let me know your thoughts. Thanks in advance for your help.

Here's the tank:

 

[wwcgroupie]

Amazing tank ! Sorry I’m not more help. I was expecting to see a tank full of large SPS can’t imagine the mangroves taking up all that CA.

 

[mcola78]

Amazing tank ! Sorry I’m not more help. I was expecting to see a tank full of large SPS can’t imagine the mangroves taking up all that CA.

Thanks! Yeah, they are little babies so can’t be them. Here’s an example of how quickly it “disappears” in under an hour, the 165ml I dosed of ALK to lift it to 7.64, already dropped to 7.33

 

[Spare time]

So you are dosing 200ml in slow increments throughout the day with a doser? I just wanted to double check that you are not dosing it by hand as that can precipitate pretty easily.

 

[Spare time]

200ml isn't that much. 1.7KH a day is very much in the common range. Some tanks use far more than that per a day. Just keep upping both parts until its satisfactory. Coralline, corals, molluscs, and other organisms will decrease alk. Even the increase of nitrate can low alk. I don't see anything wrong here. as your tank just sounds like it is making calcium-carbonate producing organisms very happy.

 

[Dennis Cartier]

Great looking tank! I don't think there is anything unusual with the amount of Alk your tank is consuming. You list a pH of 8.54, which suggests your tank is growing very rapidly. Though the tank is mixed, the SPS you do have, along with those clams and the LPS will all consume a lot of alk when happy and growing, and they appear to be both!

Is this the first tank where you have had real time Alk testing? If so, it is probably the new ability to see the alk consumption, that is making you feel that the alk decline is too great, but it is not really that big. Being able to see the alk consumption has probably allowed you to keep ahead of the curve, so to speak, and by being able to do so, you have kept your tank in a rapid growth mode. Where as in the past, you were limited by only the tests you were running sporadically (compared to auto testing).

The consumption will only grow form here if your corals (and clams) continue growing at a rapid pace. If 2 part becomes too difficult (or expensive) to supplement with, than a calcium reactor may be in your future. You will have the ability to easily provide a ton of supplementation, but your pH will probably be much, much lower than you are getting with the soda ash, and that will moderate your growth as a result. Using a CaRx with kalkwasser can help with the pH drop associated with a CaRx.

Keep up the good work!

 

[Miami Reef]

What are you using to test alk and Ca?

 

[monkeyCmonkeyDo]

...you added 20 sps frags on top.of what your tank was already consuming. I'd say I agree and this is norm.
Maybe add a calcium reactor soon...
D

 

[mcola78]

So you are dosing 200ml in slow increments throughout the day with a doser? I just wanted to double check that you are not dosing it by hand as that can precipitate pretty easily.

Correct. I did dose the single reference above of 165 over 30 minutes but normal is over 24 hours

 

[mcola78]

Great looking tank! I don't think there is anything unusual with the amount of Alk your tank is consuming. You list a pH of 8.54, which suggests your tank is growing very rapidly. Though the tank is mixed, the SPS you do have, along with those clams and the LPS will all consume a lot of alk when happy and growing, and they appear to be both!

Is this the first tank where you have had real time Alk testing? If so, it is probably the new ability to see the alk consumption, that is making you feel that the alk decline is too great, but it is not really that big. Being able to see the alk consumption has probably allowed you to keep ahead of the curve, so to speak, and by being able to do so, you have kept your tank in a rapid growth mode. Where as in the past, you were limited by only the tests you were running sporadically (compared to auto testing).

The consumption will only grow form here if your corals (and clams) continue growing at a rapid pace. If 2 part becomes too difficult (or expensive) to supplement with, than a calcium reactor may be in your future. You will have the ability to easily provide a ton of supplementation, but your pH will probably be much, much lower than you are getting with the soda ash, and that will moderate your growth as a result. Using a CaRx with kalkwasser can help with the pH drop associated with a CaRx.

Keep up the good work!

Dennis. Awesome advice. Thank you. When I dose 300ml a day it still isn’t enough to maintain. Is it realistic that a tank like this—165 gallons, growing sps-clams—could realistically consume 350+Ml of each two part a day?

 

[mcola78]

Great looking tank! I don't think there is anything unusual with the amount of Alk your tank is consuming. You list a pH of 8.54, which suggests your tank is growing very rapidly. Though the tank is mixed, the SPS you do have, along with those clams and the LPS will all consume a lot of alk when happy and growing, and they appear to be both!

Is this the first tank where you have had real time Alk testing? If so, it is probably the new ability to see the alk consumption, that is making you feel that the alk decline is too great, but it is not really that big. Being able to see the alk consumption has probably allowed you to keep ahead of the curve, so to speak, and by being able to do so, you have kept your tank in a rapid growth mode. Where as in the past, you were limited by only the tests you were running sporadically (compared to auto testing).

The consumption will only grow form here if your corals (and clams) continue growing at a rapid pace. If 2 part becomes too difficult (or expensive) to supplement with, than a calcium reactor may be in your future. You will have the ability to easily provide a ton of supplementation, but your pH will probably be much, much lower than you are getting with the soda ash, and that will moderate your growth as a result. Using a CaRx with kalkwasser can help with the pH drop associated with a CaRx.

Keep up the good work!

And yes, first time I am seeing everything real-time like this.

 

[mcola78]

What are you using to test alk and Ca?

Apex Trident. I calibrated it and did a manual test with Red Sea and numbers are close enough that I feel confident in the Trident.

 

[Miami Reef]

@Randy Holmes-Farley

 

[Dennis Cartier]

Dennis. Awesome advice. Thank you. When I dose 300ml a day it still isn’t enough to maintain. Is it realistic that a tank like this—165 gallons, growing sps-clams—could realistically consume 350+Ml of each two part a day?

Yes, as long as you are not seeing abiotic precipitation on your pumps and heaters, and your sand is not turning to rock, then the ca and alk is ending up where it is supposed to, namely in the shells of your clams and the skeletons of your corals.

2 part is excellent for dialing in your dosing and allowing you to keep your numbers in a preferred range, but it comes with some caveats. Namely the salinity creep associated with it, and the ionic shifts that long term use can cause, unless paired with a robust water change schedule.

You may want to consider moving to a 3 part by adding Tropic Marin Part C, which will remove the ionic shift issue. The BRS Hybrid Balling method does this.

If you are using small-ish dosing containers, you may want to consider to moving to larger ones, because constanly mixing and re-filling 2 part is one of the things, along with expense, that drive 2 part users nuts, lol.

 

[Doctorgori]

nothing constructive to add but I’m totally rethinking my dkh level…I get the risk and the biological chemistry but wondering if hovering in those low dkhs is so bad after all …. I’ll quit buying elevated salts anyway
….is shooting for low 7s easier to obtain? that’s more question than suggestion

edit add: that is a great looking tank, how have your colors been doing? any brighter in those low ranges?

 

[Subonidio]

Dennis. Awesome advice. Thank you. When I dose 300ml a day it still isn’t enough to maintain. Is it realistic that a tank like this—165 gallons, growing sps-clams—could realistically consume 350+Ml of each two part a day?

I had same problem .....fix it with a kalk reactor ...I love that simple piece of equipment I solved calcium and ALK at the same time .... since my tank is PSP dominated. Takes a few day to Dial in the kalk reactor but was worth it.....do I mention Kalkwaser is Cheap !!!!! I still have my Jar half full next time I'm going to buy kalk 2 wich hopefully takes care of my Magnesium!!

 

[Subonidio]

I had same problem .....fix it with a kalk reactor ...I love that simple piece of equipment I solved calcium and ALK at the same time .... since my tank is PSP dominated. Takes a few day to Dial in the kalk reactor but was worth it.....do I mention Kalkwaser is Cheap !!!!! I still have my Jar half full next time I'm going to buy kalk 2 wich hopefully takes care of my Magnesium!!

SPS *

 

[Doctorgori]

I had same problem .....fix it with a kalk reactor ...I love that simple piece of equipment I solved calcium and ALK at the same time .... since my tank is PSP dominated. Takes a few day to Dial in the kalk reactor but was worth it.....do I mention Kalkwaser is Cheap !!!!! I still have my Jar half full next time I'm going to buy kalk 2 wich hopefully takes care of my Magnesium!!

yes, you can always dose kalkwasser in tandem regardless of whatever else you do ….
I thought there were some chemical issues with that Kalk+2 … or that it can’t do what it claims or something…pardon, I don’t want to derail the thread

 

[Subonidio]

yes, you can always dose kalkwasser in tandem regardless of whatever else you do ….
I thought there were some chemical issues with that Kalk+2 … or that it can’t do what it claims or something…pardon, I don’t want to derail the thread

I agree it's nerve racking to try a new product .....but sometimes we humans like instant gratification and we as a reefers we need to try new things and evolve .....just like years back ..... I chase the 0 nutrients deal .... with catastrophic results.....never give up and before everyone start talking about more nutrients I was doing it base on observation of how my tank look like..... every coral tell us something....I have xenia in my SPS dominated Tank if stops pulsing I know I'm low in iodine.....if my montipora starts browning ....I'm low in potassium.....if my pink lemonade gets a shimmer of green I know I have to much iron.....if my tort across are loosing the purple color I know my trace elements bare low..... If my red Coraline algae starts to go white in my glass ....I know my strontium is low . But that is just me .pure observation across my 30+ years of reefer

 

[Subonidio]