Balanced Calcium & Alkalinity Levels

I have consistently seen where reefers talk about a balnce between the CA and Alk. For example, I have heard if the Alk is at 10dKh, the CA should be 450ppm or, Alk at 8dKh, the CA at 420ppm. Can someone explain this or provide a link (or 2) where this is explained? I've been dosing Alk to get the reading to 10dKh( it's there) but was trying to lower the CA to 420ppm. I'm wanting to get good growth with the SPS's I have /DesktopModules/ActiveForums/themes/_default/emoticons/smile.gif Thanks in advance/DesktopModules/ActiveForums/themes/_default/emoticons/biggrin.gif

 

Thanks guys!! I will be reading and watching this weekend :0)

 

Okay everyone, I did the reading and watching videos but I'm still struggling, at least in my mind. One of the things I learned was that one should match and keep the tanks' alk at the same level of the salt mix one uses. Do you do this?

I also had my memory refreshed on-- that low nutrient systems with SPS's should keep the alk level lower to prevent alk burn. Do you agree and follow this? If yes, what do you keep your alk at? What does your phosphate and nitrate levels average? I carbon dose daily with vinegar and have just increased to 30ml as the nitrates have gone up to about 20ppm (API) /DesktopModules/ActiveForums/themes/_default//emoticons/sad.gif Yes, you can call me "Slacker"! lol

Because stability is so important, especially with SPS's, here's where I'm really struggling...water changes! WC's can affect the alk and calcium balance...according to Randy H-Farley. The imbalance can occur upon a water change, ie .immediately or over the course of weeks or months. He states that one should correct the imbalance when it is seen. So, I've been dosing the Alk part only (BRS Soda Ash) to raise my alk to 10 dKh. {On July 30th, I tested my makeup water (Reef Crystals @ 1.026) and Alk was 11.088 using the Hanna Checker; CA was 520 -530(Elos). Is this what you get?} I do weekly water changes at about 12-15 gallons....

So keeping in mind that I have been raising the alk only ( about 10.7 - 10.8 dKh presently)...alk burn & low nutrients & vinegar dosing)...WC's affect CA & ALK 'Balance' ... my Alk has gone up a little with each WC but the calcium has REALLY GONE UP then!...about 20ppm with each WC. So what do you think?

On a final note, most of my SPS's are frags...they have been encrusting but I've seen little growth vertically and/or with branching. LPS's are growing more heads (Duncan, Hammer, Frogspawn...) but there has been no verticle/heighth growth! Why?

 

Thanks for the response David! I started out dosing Kalk a long time ago because the alk would be too low just with the WC's. I quit kalk because the CA got into the +500 range. So, I got the doser from BRS and started dosing alk. I wanted to maximize growth and thought that getting the alk at 10dKh would be a good level considering it's the middle of the range and, the level in Reef Crystals wouldn't suddenly send the alk higher in the tank upon a WC.

Although there are several answers I'm looking for, the most pressing ones are: What determines (and/or how to) the need to do a WC especially when one is carbon dosing with acceptable NO and PO levels? What level should CA be when alk is 10dKh? Knowing when dosing a 2-part, one is "suppose to" also dose Ca and Magnesium, but what effect does +500ppm CA and + 1600 Mag have on the corals?

In addition to your, David, I'd REALLY like to get several members thoughts and opinions so help me out here guys :-0)

 

Bump

 

Thanks Andy! You nailed it all for me!!! I WAS po4 limited for about 2 years...finally got some po4 to show up on ultra low phosphorus Hanna checker....then it went the other way since I had been working hard to get it to register on testing! Go figure :0) PO4 now at .03 so is getting down there again finally! NO3 are usually 0-5 but I've been slacking (trying to get the alk and CA issue resolved, dialing in doser, etc...)! I have increased vinegar/carbon dosing in the last 2 days so it's on its way to going down. I'm going to slowly reduce alk then. Will try going 2 weeks before WC and see what that does :0) Have about 3 boxes of RC still to use before switching to I/O...why not go cheaper especially when wanting lower alk and Ca?!

Thanks again Andy!! BTW, you're going to drool when you hear what sticks I'm getting! Not going to tell yet ... They have to grow up first before I let the cat out of the bag!!!