Bolus dosing

[ReneReef]

... I was dosing Kalk (1300ml) and All for Reef (25ml).

... 180 heavy sps mixed reef.

... Even before switching over I decided to start ramping up my lighting. As I did I noticed a slight drop in Alk (down to 8.1) but nothing drastic.

... I started out dosing 200 ml of KH balling and saw KH fall gradually down to 7.2 dkh even though I was ramping up dosage 50 ml every day or two. I am now at 500ml a day and have climbed up to 7.3. So not sure where I will end up.

... I have ramped up lighting using ATI Straton Pros from their recommended sps program almost 50% (mostly whites).

Thanks for sharing your observations! Much appreciated.

I've picked out a few things that got my attention.

1300 mL Kalkwasser and 25 mL AFR together contain about 300 KH units, assuming you are using saturated kalk and not kalk slurry. Using the 180 gallon as your net system volume, that would give a KH consumption of 0.42 KH per day. In my opinion, that is very low for a "heavy sps mixed reef".

200 mL of FM KH contains ~660 KH units. 500 mL contains about 1650 KH units.
So, again using the 180 gallon as your system volume that gives a KH consumption of 2.3 KH per day.
I would consider that a realistic number for a "heavy sps mixed reef".

If my interpretation is correct, then I suspect that you were under lighting your tank before starting the bolus method. Under lighting so much so that coral growth was inhibited.

Does this all sound plausible?
If you're willing to explore further, then it would be great to have more information on your lighting and the timing of the events you describe.

 

[Oldreefer44]

Yeah, a couple things. I was running a sps program from ATI which provided. It grew some corals extremely well. Staghorns and some Monti's were becoming pests and it grew colony sized Acro's at the bottom of the tank which is roughly 35 inches below the lights. The new program has increased PAR to almost 400 at about 12 inches below the surface and 300 at 25 inches. My thought is that PH was more of an issue than lighting intensity but hard to know.
I am running them at that level from 8:30 am until 3. At that point they ramp down gradually gradually turning from heavy white to more blues. KH is dosed at 8 am, CA at noon and Mg at 2.
One of the results that differs from what they predict is that PH hits it's peak at about noon and stays there until the lights shut off.
One of the other reasons I switched over was that Ca and Mg were always on the high side and this will let me dose individually.
I test every day withing 30 minutes of noon using Hanna for Alk and Salifert for Ca and Mg.
IMO, it is all about the lighting schedule and intensity and probably doesn't matter which 3 part one would use. Like I mentioned before I am very curious about the minor traces that were always deficient in the monthly ICP's. If FM's improve on them then great. If not then it may be worth looking at other manufacturers or at a modified moonshiners methodology. Thanks

 

[carbl]

Hi oldreefer,

If you are happy with the light change and the bolus dosage of the FM products, and the corals are growing and thriving, there is no reason to change anything.
However, I agree with renereef, the dosage of all for reef was very low for the tank described.
And this was certainly not due to whether KH was dosed as a bolus or continuously.
I also aim for a pH value of over 8, but there are many tanks with pH 7.8-8 that run wonderfully. A pH value of 7.9 is IMO not a problem and does not explain why the KH consumption was so low in the past.

 

[Oldreefer44]

ok, just realized that I understated the amount of Kalk dosage which was 3400ml a day to try and keep up with evaporation. Sorry. I followed FM's recommendation (I think). The interesting thing was that as I increased the dosage it would go up for a day but then fall back down a day later which has been pretty much the pattern since the beginning. Guessing I will end up in the 700 to 800 range. Let you know when it gets there.

 

[Lasse]

At last - i have been able to have a rather stable and steady day for day measurements

Tomorrow I will test with a light blast att 10 (when the light normally goes on) of 30 minutes as a start - after that - normal schedule. I plan to see if the light regime by itself will do any changings in my system. I keep the steady alk dosing-

Sincerely Lasse

 

[Lasse]

@Randy Holmes-Farley Can you please help me with a calculation. I have KH at 8 dKH. temperature at 25 degree C, sea level and normal gas pressure from all other gases, maybe higher for O2 at pH 8.2 and 8.3.

I wonder how much free CO2 I have at pH 8; 8,1; 8.2 and 8.3? I need between the thumb and the indexfinger

Sincerely Lasse

 

[Randy Holmes-Farley]

@Randy Holmes-Farley Can you please help me with a calculation. I have KH at 8 dKH and I wonder how much free CO2 I have at pH 8; 8,1; 8.2 and 8.3?

Sincerely Lasse

I don’t have the program installed, but some folks here use a program called CO2sys that I believe can calculate exact values.

As a rough guide, there is about twice as much CO2 at pH 8.0 as at pH 8.3

 

[Lasse]

Thank you - I found an online calculator here. No exact but enough for my needs.

Its interesting to see that the Bolus people prefer 8.1 - 8,2 in pH during the photosynthesis. In another thread we discuss NH4 contra NO3 as inorganic N source and which of them is the most economical to use. I´ll think there is a similar situation according CO2 or HCO3/CO3 as inorganic source for the photosynthesis there CO2 would be the most economical of them (no energy demand for transformation).


Lets look at my graphs at 12:00 today

Between 12:02 and 12:07 my free CO2 decline with around 6 % because of my addition of carbonates

Between 10:00 and 18:30 free CO2 decline with around 57 % - over 50 lower CO2 pressure at 18:30 compared with 10:00 when light was started. During this time I have dosed around 50 ml Core/:3 a+b (Sodium carbonate) How much of the pH raise is caused of photosynthesis and how much because of dosing I will try to calculate the coming weeks.

I did a test today with starting the first 45 minutes with 100 % light - after that back to my normal schedule. During this time the 100 light may be responsible for a pH raise of around 0.02 units

I have a lot of euphyllia in my aquarium. Below full light they are very expanded - showing a large area for catching photons. With my normal schedule - they are normally full expanded around 12:00-13:00, Today they was fully expanded already around 11:00

Tomorrow - I will run my 100 light for the first hour and no dosing during that time.

Sincerely Lasse

 

[SDchris]

I´ll think there is a similar situation according CO2 or HCO3/CO3 as inorganic source for the photosynthesis there CO2 would be the most economical of them (no energy demand for transformation).

Unless that H+ is really important.
Also, due to metabolic CO2, i'm assuming CO2 generally diffuses out of the cell unless active transport or enzymes are involved to keep it low.

 

[Lasse]

Unless that H+ is really important.

Can`t be - there do not exist any free H+ in water whatever we have learn in the past. The photosynthesis use H2O and CO2 in order to produce stored energy (glucose) and waste oxygen. Living in water as algae (the zooxanthella in corals) do - there is no shortage of water for the photosynthesis.

In organism using photosynthesis - CO2 is not a waste as it is for nearly all other organisms - its a resource.

The pH in any given steady alkalinity (KH) of seawater is depending on the amount of CO2 dissolved in the water - as I understand it. The amount of dissolved CO2 is mainly depended of production of CO2 (by metabolism from organisms) plus equilibrium between CO2 concentration between water and air minus consumption from photosynthesis. Leaving the equilibrium process behind (rather slow process) you can say that pH in any given alkalinity (KH) is depended of the sum of production and consumption.

Sincerely Lasse

 

[SDchris]

The photosynthesis use H2O and CO2 in order to produce stored energy (glucose) and waste oxygen. Living in water as algae (the zooxanthella in corals) do - there is no shortage of water for the photosynthesis.

But, zooxanthellae need to concentrate CO2 above atmospheric levels and have therefore evolved a way to get most of their CO2 from HCO3, and likely convert some CO2 into bicarbonate to stop it from diffusing out of the cell
The left over of this conversion is important in down stream processes (coral). In what way probably depends on which calcification model you follow.

 

[Lasse]

concentrate CO2 above atmospheric levels and have therefore evolved a way to get most of their CO2 from HCO3

May so - but still it cost energy both to get and convert - if the natural CO2 pressure decrease with 50 % the processes cost more energy. and whats with all corals that not calcify?

And note - the reson for the pH rise is probably that CO2 is consumed faster than production + air/water equilibrium.

I have often wonder why many of the best reef aquarium I have seen has been driven by calcium reactors that´s known for constant cause low pH (high CO2 concentration)

Sincerely Lasse

 

[areefer01]

I have often wonder why many of the best reef aquarium I have seen has been driven by calcium reactors that´s known for constant cause low pH (high CO2 concentration)

Can you define or expand upon what you mean by best reef aquarium?

 

[Lasse]

Can you define or expand upon what you mean by best reef aquarium?

Best growth, best calcification (especially of montipora with broad white edges), best surviving rate and good colouration.

Sincerely Lasse

 

[Randy Holmes-Farley]

Best growth, best calcification (especially of montipora with broad white edges), best surviving rate and good colouration.

Sincerely Lasse

May be a bit of chicken vs egg issue since such reactors are also well suited to supplying high alk and calcium demand tanks.

The best calcification part seems at odds with pH vs growth studies of hard corals or the idea pushed by some coral farmers to up pH significantly.

 

[Garf]

May so - but still it cost energy both to get and convert - if the natural CO2 pressure decrease with 50 % the processes cost more energy. and whats with all corals that not calcify?

And note - the reson for the pH rise is probably that CO2 is consumed faster than production + air/water equilibrium.

I have often wonder why many of the best reef aquarium I have seen has been driven by calcium reactors that´s known for constant cause low pH (high CO2 concentration)

Sincerely Lasse

I can drop my pH between 8.20 and 8.25 easily in my tank (currently 8.35 to 8.4). I've just received 3kgs of bicarb, so I should have enough to replenish any increasing Alk demand, lol.

 

[Garf]

I can drop my pH between 8.20 and 8.25 easily in my tank (currently 8.35 to 8.4). I've just received 3kgs of bicarb, so I should have enough to replenish any increasing Alk demand, lol.

PH dropped to 8.25 to 8.3 by CO2 addition, for 24hrs. No reduction or increase in Alk consumption detected (current kalk and bicarb dosing maintained), so within margin of testing error either way. I'll monitor at these settings for a while to detect trend. My snails (maybe urchin) did have a spawning event last night. Not seen that for a while, which I found interesting.

 

[Lasse]

PH dropped to 8.25 to 8.3 by CO2 addition,

When you finish this test run - if you dare - dropp it to around 8.10 and 8.15. Next test run - drop it to 8.10 daytime and much higher during nighttime. As I understand zooxanthella do not use CAM photosynthesis only C3 or C4 (I think @SDchris indicate C4 - but I do not know) - the CO2 uptake will happen during the light period. Therefore a low (8 - 8.15) pH during light period and a high pH in the dark can reveal that there were some swan eggs hiding among all the duck eggs

I´m doing some experiments like that today but I suddenly released that I have not calibrate the pH for a while. I will do that today - and see if my figures collected until now is valid or not.

Sincerely Lasse

 

[Garf]

When you finish this test run - if you dare - dropp it to around 8.10 and 8.15. Next test run - drop it to 8.10 daytime and much higher during nighttime. As I understand zooxanthella do not use CAM photosynthesis only C3 or C4 (I think @SDchris indicate C4 - but I do not know) - the CO2 uptake will happen during the light period. Therefore a low (8 - 8.15) pH during light period and a high pH in the dark can reveal that there were some swan eggs hiding among all the duck eggs

I´m doing some experiments like that today but I suddenly released that I have not calibrate the pH for a while. I will do that today - and see if my figures collected until now is valid or not.

Sincerely Lasse

I can do that incrementally. I'll get trend data on current settings first. I know @Randy Holmes-Farley has been looking for info on your proposed pH configuration for a while. My concern is perhaps a bacterial population change due to lower pH. You'll forgive me if I have the emergency exit open, with a parachute fitted, ready to bail out.

 

[Lasse]

Your tank safety in first place - always.

This is how my pH graph had look for the last years - the two last days is my tuning in to a new schedule. The pH drop during last night indicate that I probably thought right before. I use salifert phosphate eliminator. I believe it is iron based - therefore I have made sure that Core7:3 a+b which is pH raising has been dosed just before my dose of the Salifert product. I already know that liquid iron-based phosphorus precipitation products are strongly pH-lowering. Last night there was no dosage of Core7:3 a+b - the result is quite clear. Now it's off for a while - for several reasons - let's see if I was right last night. What I do now is I try to keep the pH constantly high during the night using Core7:3 a+b (KH varies by up to one unit during the day though) I turn on my lights - full blast at 10. goes down to 62% at 1:00 p.m. and at 8:00 p.m. I let my old dimming run until switching off at 10:00 p.m. The first few days have been to adapt a little

My light schedule

What I´m already have notice is that my huge euphyllia colony is fully blown already around 10:45 - it was not before 13:00 I saw this before.

Sincerely Lasse