Two Part Help

[wramy]

I am using two-part receipe #1. I am having trouble stabilizing my alk and my Ca does not seem to go down at all, something here is wrong.

Specs:
Tank Water: 190 net usg
Heavily Dominated SPS tank (120usg)
Using Elos Test Kits
Un-baked baking soda - per Randys Instructions
Kent Turbo Calcium (20%) less - per Randys Instructions

Date...........dKH.........Ca
09/16/08.....6.5.........430 <- Added 200ml Alk, 100ml Ca Part
09/17/08.....8.0.........450
09/18/08.....7.0.........440 <-5 usg Water change
09/20/08.....6.5.........450
09/21/08.....7.5.........450 <-Added 200ml Alk
09/22/08.....8.0.........450
09/23/08.....6.0.........430 <-Added 200ml Alk
09/24/08.....6.0.........430 <-Added 200ml Alk

Something seems off, shouldnt the Ca go down alot more?

Thanks for any help.

 

[Billybeau1]

There are a number of reasons why your calcium isn't dropping. I wouldn't get too hung up on the balanced issue.

If your calcium is stable with your current dosing, I would just add more alkalinity to keep your numbers within the recommended range.

Once you figure it out, it should be easy to maintain.

 

[wramy]

Even though I have not dosed any Calcium yet?

How do I know when to start dosing Ca?

 

[Randy Holmes-Farley]

Calcium declines quite slowly relative to calcium. If you are at 450 ppm calcium and need to have dosed the equivalent of 2.8 dKH over a few days, the calcium will only decline 18-20 ppm. Water changes may also keep it artificially high.

It is OK to just dose the alkalinity part, but not that calcium is being depleted, and you may find that you need to dose a larger than usual portion if you let it drift down. I'd recommend sticking to equal parts dosing unless the calcium actually gets too high, but if it does for any reason, stopping that part is fine.

I discuss such issues here:

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

 

[Shadowramy]

Thanks Randy, I will give it a read.

 

[Randy Holmes-Farley]

You're welcome.

Happy reefing.

 

[Shadowramy]

Very good reading Randy, I think I understand a bit more clearly.

So basically, when ~20ppm Ca is used, that will equally ~2.8 dkh? Therefore when I see a drop from 8 to 6 my Ca should drop ~20ppm?

I am assuming that most test kits don't measure Ca that accurately and may have a +/- of at least 20ppm thats why I am not really seeing a drop off in Ca, however, if I let it go too long I will see a significant drop off and have too make that up.

I measured today, result where alk 6.5 and Ca 430. I dosed 300ml Alk and no Ca.

In the future, whould dosing 200ml Alk a day and 100ml Ca a day be a good starting point?

Thanks again

 

[Randy Holmes-Farley]

Yes, an dyes, that is the drop, but most test kits will not allow accurate measurement of it.

If you are closely monitoring things and have confidence in your kits, then it is OK to alter the ratio to what you need, but if you do not do those things, then I'd always stick to two part. Calcium rising to 500 ppm is no real problem.

Here's the advice I give in my article:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php

from it:

http://reefkeeping.com/issues/2006-02/rhf/index.php#15

Dosing Instructions
The dosing instructions are basically the same for each recipe, although any given aquarium will end up using about twice as much of recipe #2 as recipe #1 to add the same amount of calcium and alkalinity.

To initiate dosing, first adjust calcium and alkalinity to roughly their correct ranges. This may require a substantial dose of just the calcium part if calcium is low (e.g., below 380 ppm). I would suggest targeting calcium between 380 and 450 ppm, and alkalinity between 2.5 and 4 meq/L (7-11 dKH; 125-200 ppm calcium carbonate equivalents).

This calculator shows how much of what parts to add in order to boost one or both of the parameters by a certain amount:
Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

Then, once things seem roughly correct, select a starting daily dose for routine dosing. Here are some suggested starting doses, but the exact values do not matter much. The suggested doses apply to both recipes.

After a few days of dosing, note whether alkalinity is low, high or on target. Only bother to test alkalinity, not calcium, during this period, because it is much more sensitive than calcium to over- or underdosing. Adjust the dose up or down as necessary to increase or decrease the alkalinity.

Once you have determined the proper dose, continue it until there is a substantial reason to adjust it (such as falling alkalinity as the corals increase in size). When adjusting the dose, raise or lower both of the recipe's parts together.

Resist the temptation to keep jiggering calcium and alkalinity independently. They will need occasional corrections, but that should not be the normal course of dosing unless there are substantial outside influences, such as water changes with a salt mix that does not match the tank's parameters or an error in making the mixes.

Check alkalinity fairly frequently to make sure the dosing continues at a suitable rate. Check it maybe once a week to once a month (or less as you get more experienced with the system and the tank). Check calcium once a month to once every few months to make sure it continues on track.

Remember to add an appropriate amount of Part 3 each time you finish adding a gallon of Parts 1 and 2.

 

[Shadowramy]

Thanks Randy, appericate your time.

And yes, I do not trust my kits at this time.

 

[xenon]

I don't trust any test kits at any time. lol

 

[Randy Holmes-Farley]

Thanks Randy, appericate your time.

You're welcome.

Good luck. :