dosing code

[tmgrash]

I have some brs dosing pumps coming in tomorrow. I want to figure out some code to dose properly. I need to dose 171.4 ml per day, my pumps dose at 1.1 ml per minute. So i figure 171.4x.99=169.7, 169.7/24=7.07.
So if this math is right (is it)?, I have this in mind.

Fallback off
OSC 000/7.07/52.93

Does this work?

 

[swearint]

You will want to actually measure the dose rate. Although it is rated at 1.1ml/min, the actual value may be a bit different. A measuring cup should be included with the doser. Your approach it sound, just a few issues. The OSC statement uses MM:SS rather than fractional minutes. So, in your example, 7.07 minutes is 7 minutes and 4 seconds. If you are dosing an alkalinity supplement, you should add a pH check for safety. You may also want to only dose during certain hours. Look at a graph of pH and notice the 24hr cycle. As an example, you may find that you want to dose over a 10 hr period at night (171.4 / 10 = 17.14 ml/hr, 17.14 / 1.1 = 15 minutes, 35 seconds).

[ALK]
Fallback OFF
OSC 000/15:35/44:25 Then ON
If Time 07:00 to 20:00 Then OFF
If pH > 8.2 Then OFF

Todd

 

[apjohnson]

I just did this process and I was planning to be all exact like that too, but I found that it was too difficult to get it tuned perfectly. Your consumption will change as your corals grow, water changes will throw things off, and for me, there were just too many factors to deal with to get it right. It helped me very much to document my parameters in a spreadsheet so that I could see the changes over time. Also, I struggle with high pH, so I didn't want to continue to drive my pH up so dosing is suspended of pH is above 8.4. Instead of trying to be all mathematical and trying to get exact, I get it as close as I can, do weekly tests, supplement manually if needed. If supplementation was needed, then I adjust the pump rate. I base the adjustment on the impact that prior adjustments have had (i.e. if I needed to dose 100 ml and a prior adjustment corrected by 50 ml, then I will just double the value that the historical modification made based on my historical parameter spreadsheet). Many times supplementation is not necessary, but if it is, I do so before I adjust the pump rate so I'm starting from the same baseline every time. Also, I dose calc, alk, and mag. I chose to dose them only when my lights are not on, and when the pH is below 8.4. Also, to get best mixing, I chose not have any of them dose at the same time. My code is just like the code that Todd posted, but mine is as follows:

[calcium]
Fallback OFF
OSC 015:00/012:00/033:00 Then ON
If Time 15:00 to 23:00 Then OFF
If pH > 08.40 Then OFF

[magnesium]
Fallback OFF
OSC 030:00/000:30/029:30 Then ON
If Time 15:00 to 23:00 Then OFF
If pH > 08.40 Then OFF

[alkalinity]
Fallback OFF
OSC 045:00/006:00/009:00 Then ON
If Time 15:00 to 23:00 Then OFF
If pH > 08.40 Then OFF

Note that the values in the brackets are the outlet names and not part of the code. I think the only difference that mine illustrates is how to start them all at different times.

BTW, I also use the BRS dosing pumps and I've been very happy with them.

--AJ

 

[ciphros]

I personally adjust mine based on test resuts, the number of days between tests (assuming no water changes or other confounding factors) and then use the online calculators to determine the useage rate in ml required to make that change in value. Then divide that by the number of days and that will give me a ml per day change needed. From that you can (by knowing the dose rate of the pump) determine how many more or less minutes per day you need to dose.

 

[tmgrash]

Thanks everyone, exactly the responses I was looking for. I know I'll have to adjust according to growth, etc. Currently hand dosing, morning and night. I keep records of alk, cal, and mag and usage does vary. Currently I am using about 2dkh a day. As it is my pH only swings .1 day and night, I was wondering if pH would end up be higher ovenight than daytime if I dosed all at night?

 

[ciphros]

Best thing to do is to set it up and try it. As long as you have a pH safety stop (you can set it wherever you want for pH), you will be fine. Worst case will be that you don't dose as much as you should and have to do a hand supplement. If you are testing frequently, you'll be able to know that it is needed.

Another thought, if you aren't needing to dose recipe 1 to keep pH up at night, you can do recipe 2, and then you can basically not worry about pH affects, if anything it would slightly lower it, but it is much less noticable than the recipe 1 raises pH for the same amount of material dosed. I've used both and had good Alk results. I typically have to use the recipe 1 for pH raising at night though. However, I do use the recipe 2 for manual doses if things get off by more than my liking and I don't want to cause a shift in pH.