testing KH

[Caige]

The instructions say to add 1 drop then shake... this should turn water blue.

Then it says to add 1 drop at a time while shaking tube during each until the water turns yellow.

Two questions:

1. When you count the drops to get to the total KH - do you count the first drop (the initial one that changed the water blue)?
2. My KH for the last 2 months has been at 143.2. Today when I tested it was at 107.4, what could be the reason?? All other tests come up consistent with prior weeks/months. What is best way to increase KH?

Here were my tests today... I did a PWC (10%) at 4p and then the following tests were taken tonight at 830p.

• PH 8.2
• Ammonia 0
• Nitrite 0
• Nitrate 5-10
• SG 1.024
• Calcium 320

It's a 125g tank.

Thanks for help.

 

[Kurt_Nelson]

1. Yes... count the first drop. The total number of drops you put in, until it turns yellow, is the number of "degrees Carbonate Hardness" or "dKH". (I'm guessing you're using an API test kit? If not... ignore my comment about counting drops. But either way, the first drop counts.)

2. So those numbers (I'm assuming ppm CaCO3) equal about 8.0 dKH and 6.0 dKH. Your calcium is also low. My guess is that you either have corals, or coraline algae, that are using up your calcium and alkalinity. As corals grow (and coraline algae) they will use calcium and alkalinity in fairly equal proportions. If it's not replenished, then you'll see your calcium and alkalinity numbers drop. Alkalinity can be raised by adding a buffer, but most likely you have a combination of ca/alk problem.

You can bring both those numbers up by either doing more frequent water changes, or by adding calcium/alkalinity with a 2-part cal/alk solution like Two Little Fishies "C-Balance", ESV's "B-ionic", or any of the other commerical 2-part solutions. There are also DIY solutions or bulk 2-part solutions you can buy at bulkreefsupply.com

Here's a couple good articles for you on the whole ca/alk thing.

Calcium and Alkalinity by Randy Holmes-Farley - Reefkeeping.com
Chemistry and the Aquarium

What salt are you using? If you're using a salt low in Calcium, then more frequent water changes might not do it for you, and you may be stuck with dosing the 2-part.

 

[Caige]

1. Yes using API
2. I hve been increasing the calcium slowly by PWC's... it was 300 last week. It shoud be at 340 next week.

I am using IO and I do 10gallon PWC's twice a week. (Sun and Wed). Maybe I should just change salts to one with higher Calcium.... i don't have a lot of coral... I have

- flower pot
- green duncan
- bubble tip
- frog spawn
- yellow polym
- brain

 

[Kurt_Nelson]

Even without a lot of coral, a good coating of coralline algae can suck a lot of calcium out of a tank. Is your coralline algae doing pretty good? I'm guessing it might've been, but with calcium at 300 may it was starting to turn white? (That was my introduction to keeping my calcium levels up!)

Either way... if you're keeping coral (even just a few), you probably want to keep a calcium level closer to 400. I don't think IO will do that, without supplementation. I use Reef Crystals and supplement with TurboCalcium to get my calcium levels up to 420 or so. I also use a 2-part solution to keep the levels up during the week.

I'm not saying you should switch from IO... plenty of folks with nice reefs use it. But just be aware that you're going to have to add some extra calcium to get the levels "out of the box" higher. Or of course... use a different salt.

 

[InfernoST]

If you're calcium and ALK levels are dropping of drastically on a daily basis you should test your mag levels.