DIY 2-Part Ca/Alk users - can you maintain levels? lets share some experiences

[johns]

I wanted to start a thread for those people using the home recipe 2-part (well, 3-part actually) solutions described by Randy Holmes-Farley. If you are not famliliar with this, the article is here:

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


But this thread is geared towards people who have been using it for a while now. I'd like to know:

1) which recipe are you using, 1 or 2?

2) how long you've used it

3) how much of these solutions you've been adding per day

4) what your Ca / Alk levels are

5) size tank and how heavily stocked (esp in SPS, clams, and high demand stony corals)

If you use other methods of adding Ca or Alk, we need to know that as well.

From my questions to Randy when I first started using this method, about 3 or 4 months ago, he mentioned Recipe 1 (which I use) is roughly half as concentrated as B-Ionic, so I used that as a starting point for how much of Recipe 1 to add. I doubled what I had been adding in the form of B-Ionic, so I started adding 120ml of Recipe 1 per day and could not maintian levels. I upped that to 150mls per day recently, and still not quite there I think. It may be a little closer, but I dont think it's maintaining yet.

Has anyone found a point where they can keep levels constant? I'd like to hear about it.

My system is roughly 90 total gallons and I also add about a gallon of evaporated top-off in the form of saturated Kalk solution. No Ca reactor. I consider my tank very heavily loaded in terms of SPS (over a dozen SPS I consider colonies and probably another 40+ frags actively growing out + 3 clams)

 

[steve the plumb]

I am using the aqua medic reef doser twin.I am dosing alk recipe #1 every 6hrs for 30 seconds to maintain a constant DKH of 9.I am dosing cal every 9hr for 25 seconds to maintain a level of 440 ppm.Both of the formulas are stored in a half gal bottle.I finish the alk bottle in 1 week.The calcium lasts me longer.I don't mesure the exact amount that I dose but the doser drips it slowly.I would have to take a measurement to find out exactly how much I am dosing.I use kalk with an auto top off unit to maintain ph.I have about 25 acros plus 2 brains a hammer,galaxia,2 frog spawns,zoos,richordias,elegant,scroll,motipora cap,a few leathers,a moon brain,and a flower pot.I use epson salt wich I add every so often when mag drops.I use Randy's calculator to add the correct amount.

 

[DrBDC]

I've used it for about 1 1/2 years. I don't do the try this amount method. I measure my dKh daily for awhile, figure the daily amount of drop which is 1 dKh w/limewater for all my evaporation which adds to about 3 gallons per day right now. After a week of daily measuring you get an idea of the daily amount needed. Then move to 2X a week testing to see if those daily additions are creeping up or down. If you did the initial daily testing long enough to get a consistant number it should be corrrect. Now I do about 1 X a week or less and it stays correct. As the seasons change I get a little creeping of the numbers and just adjust up or down. The only reason for the number changing much is larger corals, hopefully not less corals!, and change in evaporation since the limewater amounts added are dependant on that i.e. more evap = more ca/alk added via the limewater. Now if you set the limewater addition to a set amount, that would keep most drifting from occurring and there would be more freshwater to add during high evaporation seasons. Or if you don't dose lime for topoff then it would be more consistant as well. BTW I use formula 2 since I dose limewater which keeps my pH correct and I don't need a pH boost.

Unless you are doing waterchanges with salt mix that has incorrect balance of ca/alk that is not precorrected(?) before adding to the tank, you should always add equal amounts of part A and part B or you will drift out of balance. Many think the ca is not dropping in comparison to the alk but it's not true. You get about 18-20 ppm drop for every 2.8 dKh IIRC and 20 ppm is within the "noise" factor of most ca test kits so you probably don't even read it correct.

 

[Randy Holmes-Farley]

FWIW, the amount needed will depend entirely on what is in the tank (and other aspects of the setup), the pH, and the desired alkalinity. Higher alkalinity and pH result in higher demand by corals and by abiotic precipitation. Low magnesium will also increase abiotic precipitation, increasing apparent demand.

 

[steve the plumb]

I never test the water I am adding,I only test the salinity.

 

[DrBDC]

Test at least 1X per bucket and then correct it before adding, it will let you get a better idea of actual daily/weekly consumption by your tank and then you don't have to give unequal portions of part A/part B. That will also stop from having up/down swings every time you do a water change. Unless you compare your tank water to fine wine and go by what year it was produced.

 

[steve the plumb]

I test tank water twice a week.I have a brute container wich I fill with salt water so I use it and refill when its emty.I always have a steady calcium and alk level.I dose more alk then calcium but not that much more.I like to keep the DKH at 9.I should test the water I am adding but I figure I test the tank so why bother.Call me lazy I guess.

 

[Froggy]

I have been using Recipe #1 for almost 2 months now on my 75 gallon. I also drip 1 gallon of kalk at night. I switched to the recipe #1 from B-ionic. I initially thought I would need more of the DIY solution than B-ionic. I used to dose 120 ml of B-ionic and 1 gallon of kalk daily to keep my levels up and initially raised the dosing of recipe #1 up 60 ml per day over the B-Ionic dose. ( dosed 180 ml of recipe #1 and 1 gallon of kalk daily). I found that my alk was increasing too high for my taste by dosing this much and my tank tested calcium 450 ppm, alkalinity 13.6 DKH, and magnesium 1365 all with Salifert.
I decided to lower the daily dose over the last month back down to 120 ml of recipe #1 and 1 gallon of kalk daily and my tank has now tested stable over the last 3 weeks at 460 PPM calcium, 9.6 DKH alkalinity and 1365 PPM magnesium.
For the calcium portion of the recipe I have been using Prestone driveway heat de-icer as I could not initially find Dowflake. So far I could not be happier with the DIY recipe provided by Randy. It is easy to prepare and of course a lot more cost effective. Thanks Randy !!

My Calcium does seem to slowly raise higher and higher with equal additions of the DIY recipe # 1 . I chalk that up to personal measuring error when I mix the soluton as it is diffucult to measure the exact amount with the Prestone pellet product as the pellets are not uniform and equal in size.

 

[johns]

Well this is all helpful, but it also brings up a number of questions I have. Let me sort through this one by one.

Steve the plumb - I am using the Aquamedic Dual reefdoser as well. This doser is supposed to dose at a rate of 1.5L/hr or 25ml/minute. However, be careful with those figures - the same company makes a separate pump which doses at 2X that rate and apparently some of the dual reef dosing pumps were out on the market for sale using those other pumps by mistake (I know, I got one. I returned it and got one with the right pump). Also, I measured my dosing rates and while one pump was dosing at around 25/ml, the second was more like 30-32 ml/min

Anyway, just assuming yours doses 25ml/min as it should, you are dosing about 50ml of Alk per day, and a bit less of the Ca. Seems like you dont need to dose nearly as much as me, but I guess all our systems are different.

DrDBC - I am very interested in what you are saying here. I've heard this mentioned before, and it all sounds pretty straight-forward. But the info I need is to translate how much to increase the dosing amount in terms of how much the Alk is falling. I never find this info anywhere, so I wind up with the 'try this amount' method.

For instance, I increased my dosing to 150ml/day of each solution about a week ago. I tested levels for a starting point and then again 4 days later. Starting out dKH was around 11, and 4 days later it was about 9.5 (I dont have the exact numbers, but I can get them later). But just going with those for now, that is a drop of about 0.375 dKH per day. So now, how do I translate that? How much more Alk solution do I add per day to offset that. If I know the calculations, I can use my actual numbers later to do this . And I'll probably do a few more testing points first too, in order to confirm that is the actual rate of decrease in the dKH.

After I get the dosing rate right, my next step will be correcting the water for changes and pre-correcting that before adding.

Randy H-F:

What do you mean by this:
Higher alkalinity and pH result in higher demand by corals and by abiotic precipitation.

The higher the dKH level in your tank and higher the pH, the more solution your corals NEED? So, by adding more, the result is the corals need still more? Please explain.

I would love to set a level that I want Alk to be at, but I just want it to be stable first of all. Then I was thinking I could just adjust it where and want it and maintain. I guess I was hoping to get Ca at 420-430 and Alk at around 9.5-10.0 dKh. With that in mind I dont know if I should be proceeding differently than I have been.

 

[Froggy]

johns, I am not sure of your total water volume but using this calculator http://home.comcast.net/~jdieck1/chem_calc3.html
it looks like you will need about 56.2 ml of the alkalinity part of recipe # 1 to raise your total tank alkalinity .375 DKH from 9.5 to 9.875 in a 75 gallon system. You could try adding an additional 56 ml of the recipe #1 to what you are currently dosing and see if the demand and dosage evens out a bit. At least I think I am figuring that correctly .

 

[johns]

Froggy- Yes I see, it's very simple. I thought of that right after I clicked submit - "USE THE CALCULATOR"

I tried it and didnt get the same numbers as you. I think you went from 9.5 to 9.875 in meq/l instead of dKh. I think the number is actually 20ml to raise dKh by 0.375 in a 75 G system.
But thanks.

 

[Froggy]

DOH !!!! sorry about that ..... You are correct I forgot to change the calculator to DKH. sorry for the incorrect dosage but glad to see you double checked You are correct 20 ml in DKH.

 

[steve the plumb]

I set up my doser with trial and error.It took me a few days to figure out the correct amount.I dose by the seconds and I find the unit drips slowly and so far I am happy with it.I was lucky in that it didn't take me long to get the correct dosage.

 

[Randy Holmes-Farley]

What do you mean by this:
Higher alkalinity and pH result in higher demand by corals and by abiotic precipitation.

The higher the dKH level in your tank and higher the pH, the more solution your corals NEED? So, by adding more, the result is the corals need still more? Please explain.

Yes, that is exactly what I mean. Corals calcify faster at higher alkalinity and higher pH. It is a negative feedback, limiting the rise on adding more, and reducing the drop on adding less. It is luck for aquarists that this is true, IMO, as it makes exact dosing less critical.

 

[johns]

So, is it true that higher Alk and pH levels = faster growth rate? That is not so surprising.

Or at higher Alk and pH do they just need more to keep up at the normal growth rate?

 

[DrBDC]

johns, what I was saying is measure your levels, dose appropriate amounts to get where you want. Then the next morning, check the dKh. If it fell by X amount, add equal amounts of a and b to fix that. Check again same time tomorrow. Did it drop the same? Or a slightly different amount. Add the amount to fix that. Keep doing that for a few days and you'll find the daily usage. Then you can go for a few days adding that same amount you had been. Check again. Has it stayed level? If so you already have your daily amount needed. Or you make an adjustment. Use the chemistry calculator it will tell you the exact amount to add for each of the times you test it to get it back to your baseline level.

 

[Randy Holmes-Farley]

Or at higher Alk and pH do they just need more to keep up at the normal growth rate?

They calcify (grow skeleton) faster.

 

[Randy Holmes-Farley]

This thread discusses pH concerns for calcifying corals in the ocean:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=782336

and this article discusses how a number of factors relate to calcification rates:

The Chemical & Biochemical Mechanisms of Calcification in Corals
http://www.advancedaquarist.com/issues/apr2002/chem.htm

 

[Redfish]

I use Randy's two part recipe with an Aqua Doser. I dose ten times per day (2:24 intervals). The tank is a 225 gallon full blown sps reef tank that consumes between 450-600 ml of each part per day. I have been dosing Randy's two part long before his original comprehensive article was published.

I test alkalinity/calcium/magnesium about once every 10-14 days and adjust my on times for each pump.

I have found that the temperature of my tank plays an important role in alk/cal requirements. I do not heat or chill my tank. The tank stays right around 78-79 during the summer, but drops in the winter to a more variable range of 72-75. My alk/cal consumption in the winter can drop quickly.

I also, occasionally have a pH drop in the tank that lasts for a few days to a week. This also affects alk/cal consumption. I am unsure what causes this drop, but I believe it is either related to carbon dioxide in the house or the amount of "clean water" algae in my tank.

 

[johns]

Redfish-

Good info. Wow - Thats a lot of solution per day.

I take it you dont do kalkwasser? How about a Ca Reactor?