Low Alk consumption

carri10

Active Member
View Badges
Joined
Sep 19, 2022
Messages
373
Reaction score
270
Location
Strasbourg
Rating - 0%
0   0   0
Hello.
I have a question on alkalinity consumption levels.
(I also have a question on variation of consumption, that is in another thread I have just posted.)
This thread is on the absolute levels of consumption.
I dose 70 mls per day of Randy’s three-part version 1.
For the alkalinity part from Randy’s recipe, if my maths are correct, this 70 mls is equivalent to 0.28dKH per day.

http://reefkeeping.com/issues/2006-02/rhf/index.php

Here it states that the stock is 1,900 meq/L of alkalinity (5,300 dKH).
I add 70/1000 * 1900 meq per day = 133meq into my tank of 1250L
Therefore I add 0.1meq/l/day
As 1meq = 5300/1900dKH (2.79) this means my tank consumes 0.28 dKH / day
(Note, I dose the corresponding amount of Ca and that stays rock solid over a weekly basis at 430ppm).

This seems very low for a tank that is
- 9 months old
-has 11 sps (inc 5 montis)
-11 euphyllia
-7 cyphastrea
-about 20 other corals.

PAR varies from 250 down to 50 from the top rocks to the bottom, provided by 4 x GHL lightbar 3, 12 hour photoperiod, with a 2 hour ramp up morning to 14000k (I think) then about 6 hours full power, then a transition into more blues for the evening.

pH varies from about 8.1 to 8.4
Conductivity is around 34.5
NO3 are 10-20
PO4 is 0.07-0.1
I attached my latest ICP.
I dose Micro E, 20 drops per day.

Corals get fed BRE reef chilli once or twice a week.

Flow is 2 x Maxspect 350, 2 x tunze stream 3+ and a Jebao MLW-30

My corals do grow, but slowly.

Why is my alk consumption so low?
Have I made an idiot of myself with the calculations?
Any opinions welcome!


IMG_0159.jpeg
IMG_0160.jpeg
IMG_0161.jpeg
 

Attachments

  • analysis-192893.pdf
    274 KB · Views: 55

Randy Holmes-Farley

Reef Chemist
View Badges
Joined
Sep 5, 2014
Messages
89,230
Reaction score
92,238
Location
Massachusetts, United States
Rating - 0%
0   0   0
Calculations are correct.

You have a lot of open water, which effectively raises the water volume and reduces the per gallon alk demand.
 
OP
OP
carri10

carri10

Active Member
View Badges
Joined
Sep 19, 2022
Messages
373
Reaction score
270
Location
Strasbourg
Rating - 0%
0   0   0
Thanks for the verification.
So you don’t think that my alk consumption (which I am using as a short time frame proxy for coral growth) suggests they are growing significantly slower than their potential ?
 

Randy Holmes-Farley

Reef Chemist
View Badges
Joined
Sep 5, 2014
Messages
89,230
Reaction score
92,238
Location
Massachusetts, United States
Rating - 0%
0   0   0
Thanks for the verification.
So you don’t think that my alk consumption (which I am using as a short time frame proxy for coral growth) suggests they are growing significantly slower than their potential ?

They might calcify faster at different conditions, but I don't see a reason to be concerned.
 

TOP 10 Trending Threads

WHAT AMOUNT OF LIVE ROCK AND SAND SHOULD BE PRIORITIZED FOR OPTIMAL BIODIVERSITY/FILTRATION?

  • 100% live rock + bagged sand

    Votes: 34 28.1%
  • 100% dry rock + 100% live sand

    Votes: 41 33.9%
  • 50/50 live/dry rock, 50/50 live/bagged sand

    Votes: 27 22.3%
  • 75% live rock, 25% live sand

    Votes: 11 9.1%
  • 25% live rock, 75% live sand

    Votes: 8 6.6%
Back
Top