Two-Part Dosing - Rookie Question

I've gone both routes back and forth for many years. If I don't have a dosing system setup then I use the off the shelf stuff as it provides buffering that tends to reduce fluctuations in the system params while dosing. It seems we are all in a hurry and so hand dosing usually means dumping it all in at once.

If I have a dosing system in place then I always use the bulk 2 parts (or inexpensive equivalents) as my doser will spread it out over time and not shock the system without the use of buffers. So my answer is..... it depends.

Krazie

Thank you both (Krazie4Acans and Reefdup).  If I am understanding you both correctly, as long as I have dosing pumps in place to spread the dosage of 2 part out over a few hours or more, start with a low dose, and test daily to determine the amount of dosing required, I should be fine?  So the off the shelf stuff is a bit safer just because of its buffering abilities?  I have an opportunity to buy two brand new BRS pumps for $100 from another WMAS member.  Comparing that to what I spend at the LFS, they would pay for themselves (minus bulk chemicals) in 2 or 3 months. 

Jay , on my first set up it seemed that I chased my own behind trying to keep my params where they needed to be , So I actually spent more of my time and more on test kits than was needed. Get dosing pumps then start with simple 2 part and as you learn more about dosing with pumps I'm sure other who dose from homemade supplements will share their recipes and amounts to dose. I personally use BRS 2 part .

Thank you for that input.  And coincidentally, I am also an Engineer, not a Chemist.  Also, I didnt do enough research.  I purchased the same pumps you were looking at tonight.  I did not realize that I need a very accurate timer or a controller.  I do not have a controller, and not sure when I will be willing to cough up the $300-$500 to pick one up.  I have found digital timers that will do one minute increments, but not sure I want to trust them.  So I am going to try to brainstorm some things that I can "engineer" to utilize the pumps without a controller.  But on that topic, if you are still debating them, I might be willing to sell them and wait until I have the cash to buy a controller, and pick up the pumps then, even if I had to pay full price.  

Akira wrote: Jay , on my first set up it seemed that I chased my own behind trying to keep my params where they needed to be , So I actually spent more of my time and more on test kits than was needed. Get dosing pumps then start with simple 2 part and as you learn more about dosing with pumps I'm sure other who dose from homemade supplements will share their recipes and amounts to dose. I personally use BRS 2 part .

Jeremy, Keep the pumps. Even if you run them on 15 minute timers 4 times a day (remember they only dose 1.1mL per minute) that is better than measuring with a beaker and dumping (especially with alk and it has significant impact on pH). Keep the pumps get the digital timers that got down to 1 minute and use them. They will be more accurate than you think and much more forgiving on your system than beaker dumping. The controller can come later.

Krazie4Acans wrote: Jeremy, Keep the pumps. Even if you run them on 15 minute timers 4 times a day (remember they only dose 1.1mL per minute) that is better than measuring with a beaker and dumping (especially with alk and it has significant impact on pH). Keep the pumps get the digital timers that got down to 1 minute and use them. They will be more accurate than you think and much more forgiving on your system than beaker dumping. The controller can come later.

I follow Dr. Holmes-Farley's recipe for making two part, and then I use a reef calculator online to determine how much I need to dose. You just type in your measured values, ideal values, system water volume, and product (Randy's Recipe in my case)...and voila, the calculator spits out exactly how much you should dose. I am on my phone so I will post links later. Dosing is much more easy than people make it sound.

It definitely depends on livestock load. If you calculate your daily usage rate, it is easy to calculate your daily dosing requirements. There is rarely a need to test more frequently than weekly...and once you have the hang of it then monthly testing should suffice.

As an example, water changes are sufficient for my quarantine tank, but I have to dose nearly 300 ml per day of calcium on my display tank. My display is much larger...has a ton of sps and a clam. My quarantine just has a bunch of teeny frags that do not require much.

Ok, I got tired of trying to type on my phone...I'm at my computer.

I wrote up this little blurb on my website on how to mix up the two-part solution based on Dr. Randy Holmes-Farley's recipe. So, mix that up first of all. This will create a solution with a known chemical level which can then be used to dose the correct amount.

http://www.reefdup.com/2012/12/16/how-to-make-2-part-dosing-solutions/

Then, test your water. Use the website below to calculate your dosing requirement:

http://reef.diesyst.com/flashcalc/flashcalc.html

So, as an example, if you measured 7.8 dKH alkalinity, have a system water volume of 100 gallons, want your alkalinity at 10.0 dKH, and used Randy's Recipe 1 Alkalinity Part, then you need to dose 157.1 ml of the alkalinity supplement you just made.

Retest about an hour later (keep in mind that you shouldn't dose high amounts at once). Dose more if required to get your chemicals to your desired levels. Your solutions may not have been mixed fully, you might've used a less potent chemical, etc....so slight variations may occur (but nothing significant).

Once you have your parameters where you want them...stop. Wait several days (I prefer 4 days) without testing or dosing (keep replacing evaporated water though!)

Retest. As an example, say you started at 10 dKH on Day 1, and on Day 4 you were back down to 7.8 dKH. Replug your numbers into the reef calculator. You should get 157.1 ml required. Dose that amount. You should have your alkalinity back up to 10 dKH. Then, divide the dosing amount required by the number of days without dosing (so, 157.1 ml divided by 4 days is just over 39 ml/day).

If your pump doses 1.1 ml per minute, you'll need to dose for about 35 minutes each day given those example numbers.

Retest weekly until you're confident in your pumps, calculations, etc. After that, retest and adjust monthly. As your corals grow, so will the need for additional supplements.

Here's the science behind all this:

http://www.advancedaquarist.com/2004/4/chemistry

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