Low Dkh 5.1 high PH C Balance dose rising while Cal/Alk keeps dropping Could be precipitation?

[Rafeh]

Hi I'm having difficulty rising my Cal/Alk levels i have increased dosing from 55ml to 200ml 116 gallon tank.
Previously 55ml to maintain DKH 8.0 and PH 7.7-7.9 up until 10.02.2020 when i noticed C Balance Part B was not being added by Apex dosing pump as tube was not fully submerged in bottle.

10.02.2020 DKH 5.1 PH 7.82 In order to counter Part A started Dosing Part B extra from 55ml to 80ml over few weeks while part A remained 55ml
12.02.2020 Added C02 Scrubber
Current parameters 04.05.2020 with 200ml C balance 1:1 A and B
Salinity 34ppt
12hrs later DKH 5.5 at 23:45 PH 8.28
DKH 5.7 at 11:45 PH 8.15
Calcium 415
Mg 1290

Please help me understand what is going on with my tank and how to fix this issue. By the way most of corals are still growing faster while 2-3 have partial bleaching.
Its SPS dominated tank i have 3 colonies and rest frags i can share picture there is a lot of coralline algae.

System
Red sea reefer450 116 gallons total system volume (actual water volume unknown)
Skimmer, Bio reactor (2 little fish bio pallets in small amount)
Reef Octopus LR-150 Cheato Algae Reactor
Chiller
Marine pure block and balls
Phosban Reactor
C02 Scrubber
Ozone generator
Light settings from 10:00 till 23:00 I also get indirect sunlight throughout the day

Supliments and Salt
red sea coral pro
Acro Power 15ml/day
Iodine 5ml/week
fauna marin min S 2-3 per week
Vibrant used only 2 times once after every 2 week

Detailed History

02.04.2020 DKH 7.0, Calcium 425, Salinity 35ppt, C balance Increase Part A and B to 85ml 1:1 ratio back to normal
10.04.2020 DKH 6.7, PH 8.41, C Balance increased to 100ml
19.04.2020 PH 8.4, ORP 250 Installed ozone generator
20.04.2020 DKH 7.20
24.04.2020 DKH 6.0, 40L water change Coral pro salt
25.04.2020 DKH 6.2 at 16:00hrs
28.04.2020 DKH 5.3 at 10.30pm Increased C Balance from 120 ml to 140 ml time 23.00hrs
30.04.2020 DKH 5.3 at 13:00hrs, Calcium 415, Phosphorus 0, C Balance Adjusted from 140 to 160 ml at 17:00hrs
01.05.2020 DKH 5.2 at 15:11hrs, C Balance dose adjusted from 160 to 180 time 22:50
02.05.2020 DKH 5.1 time 12:00hrs, Calcium 410 Possible cause precipitation issue due to location (skimmer chamber in Sump) and dosing C balance at same time without interval.
Changed dosing interval to 5mins and location to Display tank near high flow 16:30-17:00hrs
DKH 5.1 at 22:15hrs
03.05.2020 DKH 5.2 at 03:50hrs, DKH 5.3 at 12:40 PH 8.14 ORP 343, DKH 5.1 at 20:35hrs PH 8.31 ORP 334, Water change 40L 23:00hrs, DKH 5.5 at 23:30
C Balance Increased dose from 180ml to 200ml/day from 00:00-23:50 every 15mins with 9 mins interval between Part A and B

Thank you for all the help i can get

 

[Randy Holmes-Farley]

Do you see signs of precipitation anywhere/

hardening sand? Pumps impellers seizing up with coatings?

heater with a big shell of precipitate on it?

 

[Rafeh]

Hi Randy Sand bed is not hardening i also syphoned in small batch before water changed no pumps are seizing although i find sand like particles on my sump walls i will share images.

 

[Rafeh]

 

[Randy Holmes-Farley]

For a 116 gallon tank, 83 ml of C-balance is 1 dKH.

I can't really tell how often you are dosing these amounts.

1 dKH per day is not excessive. More than 2 dKH or 3 dKH per day may be, depending on the coral growth rate.

 

[Rafeh]

For a 116 gallon tank, 83 ml of C-balance is 1 dKH.

I can't really tell how often you are dosing these amounts.

1 dKH per day is not excessive. More than 2 dKH or 3 dKH per day may be, depending on the coral growth rate.

right now it's 1.72/gallon dosing after every 15 mins with 9 mins of interval between part A and B

 

[bobssecrtsn]

Does salinity play a role in Dkh? What is your salinity at?

 

[Randy Holmes-Farley]

Does salinity play a role in Dkh? What is your salinity at?

I'm not sure exactly what you are asking. dKH only relates to salinity in that, like everything in the water, it rises or falls if you allow salinity to rise or fall with no other additions or consumption.

 

[Randy Holmes-Farley]

right now it's 1.72/gallon dosing after every 15 mins with 9 mins of interval between part A and B

Can you clarify exactly how many mL of B-ionic alk part you dose in 24 h?

 

[Rafeh]

Can you clarify exactly how many mL of B-ionic alk part you dose in 24 h?

220 ml B-ionic Alk as of now in 24hrs.

Discussed this issue with Julian Sprung he suggested
" add some sodium bicarbonate to raise the alkalinity to about 7.5 dKH and then continue to dose C-Balance parts A and B in equal amounts daily. He has to remember that as the coralline algae and corals grow they will consume more and more calcium and alkalinity, so the dosing will need to be increased over time. Looking at the tank I believe that about 80 -100 ml of each part daily will be about right for now"

Im thinking of dosing Two little fishes KH Power what I'm trying to figure out is how much i should dose per day and would it be safe to rise 0.5 Dkh per day? friend of mine suggested 250ml per day

 

[Randy Holmes-Farley]

220 mL of B-ionic is about 4 dKH per day. That does seem excessive unless you have a lot of rapidly growing hard corals and coralline algae.


The only other sink for alk and calcium (assuming your kits are accurate) is abiotic precipitation.

To limit precipitation you want to:

Stop dosing as long as alk stays above 6 dKH (corals are typically Ok at that level). When you resume dosing, use a low pH additive (like baking soda). Stop efforts to boost pH (if any). Reduce skimming or other organic removal temporarily. Keep magnesium at least 1300 ppm. Let calcium drop. Remove phosphate export methods if using GFO or other binders.

 

[Rafeh]

Randy 5.4dkh this evening how did you calculate 4dkh? i thought 220mL/day for 116 gallon is 1.89dkh yes I'm having rapid growth even small frags are branching surprising for me and yes there is coralline algae and i have Clam in tank could it be culprit? Few sensitive corals such as home wrecker is not opening up but are surviving.

 

[Randy Holmes-Farley]

Randy 5.4dkh this evening how did you calculate 4dkh? i thought 220mL/day for 116 gallon is 1.89dkh yes I'm having rapid growth even small frags are branching surprising for me and yes there is coralline algae and i have Clam in tank could it be culprit? Few sensitive corals such as home wrecker is not opening up but are surviving.

I can't remember exactly what I did and may have confused two threads, but I used this calculator:

Reef Chemistry Calculator

enter 116 gallons and 220 ml C-balance and get 2.7 dKH.

I think I probably entered B-ionic instead of C-balance.

That 2.7 is not nearly as high.

 

[Rafeh]

Hi just quick update as my C balance bottles finished i started dosing same amount 300ml with new bottle suddenly in 12hrs my DHK spiked 0.8dkh this mean the C balance i was using was defected and had low potency.

Now im dosing 125ml/day with dkh @ 8.3

Problem solved it was bad batch of 2 part.