Bolus dosing

[ReneReef]

Ok I’ll do some testing today and report back. I switched my Bolus dose off for today and I have just run a test and kh is now 7.6. It’s 08:41 in the UK

That would be great. In the mean time I think some interpolation is in order.


I see one problem in the interpretation. That is using the 1 dKH change as daily consumption, while the bolus dosing and KH measurement points are not aligned. So, the 1 KH is actually measured over 18 hours and not 24 and some interpolation is in order.

If assuming, the FM calculator is wrong, the KH mix is 100 grams of bicarbonate per liter, then a dose of 250mL in 650L would give a KH rise of about 1.285.

Exemple time line on october 14th:
6:00 AM KH measurement 7.7
8:30 AM Bolus dose
9:00 AM lights on Bolus style (120%)
12:00 PM KH measurement 8.7
6:00 PM KH measurement 8.2
12:00 PM KH measurement 7.8

From 6 to 8:30 the KH will drop slightly below 7.7.
These 1.5 hours are problably negligible, maybe 0.05-0.1 KH, looking a the data from other days.

After bolus dose and lights on the dosed KH will be consumed during 3 hours before the next KH measurement at noon. Additionally, the max light output should (according to the Bolus manual) be during the first few hours after the bolus dose.

So at least 0.5 dKH consumption in 6 hours. Or 0.25 in 3 hours. Likely a bit more because of the higher light intensity during the period. This means that the peak KH directly after dosing the bolus dose was likely close to 9 dKH.

Therefore, the daily KH drop would in my opinion more likely be 1+0.25+a bit more+maybe 0.05 = ~1.28 to 1.29 KH consumption a day.

 

[ReneReef]

P.S. of course 6 to 8:30 is 2.5 hours. Mornings are not my best time of the day

 

[andrewb70]

Ok just had a noon kh test and it is 7.3. yesterday at noon was 8.8 so circa 1.5 usage over 24 hour period. This is with Bolus dose off. I plumbed that drop into the Fauna Marin Calculator and it says I should be dosing 195ml per day so something slightly off there !

I maybe off with my tank volume of course (48x21x27) 425 litres plus sump (48x15x18) 90 litres half full. Frag Tank (36x15x24) 210 litres. So around 720 litres without displacement and equipment.

I will stay at 250ml and run some more testing during the week.

 

[Randy Holmes-Farley]

I plumbed that drop into the Fauna Marin Calculator and it says I should be dosing 195ml per day so something slightly off there !

The problem is likely their faulty info on potency.

 

[Lasse]

Unfortunately, my KH director broke a few weeks ago. Haven't replaced it with a new one. During the last week I have measured manually in the morning and evening - Alkalinity is around 8.6 dKH at 10:00 and drops to around 7.6 at 22:00. I have measured the pH during the last week and compared it with my dosage which only happened between 10:00 pm and 10:00 am (10 pm to 10 am). The light schedule has been - full blast between 10:00 and 14:30 and then 65% until 22:00.

Light schedule

result in pH

From today - I have changed my light schedule to my normal - like this

I will follow this up during next week

Sincerely Lasse

 

[djf91]

Not sure if this exact point has been discussed already given all the talk about lighting but here’s something I’ve noticed.

Two weeks ago I increased my photoperiod by 1.5 hours going from 6 hours with my metal halides to 7.5 hours. Since then I’ve noticed a full .1 shift upwards in my pH. I run pretty intense metal halides but the corals have responded with more polyp extension and more intense colors and maybe more growth. I think this aligns with the photoperiods people used to run back in 90-00’s where some people ran 12 hours of metal halide per day. I think just running a longer photoperiod will result in higher pH thus causing healthier corals/ more growth.

Sorry if this has already been discussed.

 

[Lasse]

the corals have responded with more polyp extension

For me and IMO - this is a sign of increased photosynthesis - the corals needs more area for the diffusion of excess oxygen production from the photosynthesis. This in itself does not necessarily mean better health status. just that more surface area is needed to increase the diffusion of oxygen per unit of time and thus reduce the risk of the formation of oxygen radicals that can damage (burn) the corals.

Sincerely Lasse

 

[ReneReef]

Not sure if this exact point has been discussed already given all the talk about lighting but here’s something I’ve noticed.

Two weeks ago I increased my photoperiod by 1.5 hours going from 6 hours with my metal halides to 7.5 hours. Since then I’ve noticed a full .1 shift upwards in my pH. I run pretty intense metal halides but the corals have responded with more polyp extension and more intense colors and maybe more growth. I think this aligns with the photoperiods people used to run back in 90-00’s where some people ran 12 hours of metal halide per day. I think just running a longer photoperiod will result in higher pH thus causing healthier corals/ more growth.

Sorry if this has already been discussed.

Your observations are completely logical.
pH in our tanks is determined by CO2. Increasing the photoperiod or light intensity means more photosynthesis and more CO2 consumed and consequently a higher pH. Although, the pH increase by more lighting is limited by the CO2 available in the water.

In effect, all the pH increasing measures we can employ lower CO2.

The Bolus method calls for two things a change in KH dose timing and an increase in lighting. It has been discussed here at length that the pH gain is most likely due to the increased lighting and not the bolus dose.

Lasse is experimenting to separate the effects of the lighting increase and the bolus dose.

 

[Hans-Werner]

corals have responded with more polyp extension

More polyp extension means more light exposure of the zooxanthellae. I think it is generally accepted that this is the background of polyp extension of zooxanthellate cnidarians.

In my experience more polyp extension is often associated with lower pH/more CO2, phosphate availablility/dosing and in this way generally better conditions for photosynthesis. Polyp contraction means the opposite and more "self shading" of zooxanthellae.

Polyps are generally more open in the night and in the morning (lower pH), so the time of the observation has to be taken into account.

 

[Pod_01]

lower pH/more CO2

So out of curiosity, what do you consider to be lower pH range that can enhance/ help with polyps extension?

 

[Lasse]

Night open polyps - feeding behaviour. Open polyps during light probably not a feeding behaviour (because normally lack of anything to feed - at least in nature) and it is risky according predation from polyp eating animals. There must be a reason why some acropora species sometimes show their polyps in full light. To maxim the light exposure to the zooxanthella inside polyps (zooxanthella exist in the normal skin too) can be one reason but the the mechanism of getting rid of oxygen is often underrated IMO. When LPS expand their body (and also for soft coals with photosynthesis) is IMO both to enlarge the photon catching area and get rid of surplus oxygen produced of the altered rate of photosynthesis.

Sincerely Lasse

 

[Hats_]

So out of curiosity, what do you consider to be lower pH range that can enhance/ help with polyps extension?

lowering the pH for polyp extension seems counter-productive to me. the point Hans was trying to make is that polyp extension is not a measurement of coral health necessarily.

 

[Lasse]

Lasse is experimenting to separate the effects of the lighting increase and the bolus dose.

Yes - but I do not get the expected result - as it looks like now - my total photosynthesis expelled as pH seems to be higher with my normal light schedule. Experiment will continue.

KH (7.8 - 8 dKH at 20:00) have been stable during the whole period. So also the dose amount of Core 7:3a+b

Sincerely Lasse