How much can I dose safely,using " a balanced " 2prt ??

cracker · Oct 13, 2017

1st let me say I tried a search for this & came up with not too much. So Due to an old test kit I was getting a false high ALK reading I used 2 new kits to verify. So the old kit gave me a 7.6 alk. the 2 new kits gave me a 6.5 reading . I'd like to throw by my plan to see what Ya'll think.
So according to JDieck's calculator I'm to dose 102 mls of part 2 to bring Alk from 6.5 to 8.1 . I plan to dose 80 mls & see what I get. I will add 40 mls now & 40 tomorrow. However My Ca is right on the mark.( However this is from the same old kit so is suspect as well.) Now this Ocean's Blend is balanced . I'm planning to add the same amount of Ca as well. This will jack the Ca way up and concerns me. What do Ya think? Thanks !

LobsterOfJustice · Oct 13, 2017

If you only need to raise Alk, only add Alk. The balanced part is to make it easy based on the ratio of normal consumption. But if you are correcting imbalanced numbers, just use one.

cracker · Oct 13, 2017

makes sense ! Thanks. still undecided at this point.

Randy Holmes-Farley · Oct 14, 2017

Let's put that calcium rise in perspective lol

It will not "jack the Ca way up".

You are asking about raising alkalinity from 6.5 to 8.1 dKH. A rise of 1.6 dKH.

A perfectly made two part dosed in equal parts for that rise will boost calcium by about 11 ppm.

So if you are perfect at 420, it becomes 431 ppm, which is still perfect, and probably not even a difference you can accurately measure.

Yes, you can dose just the alk part if you are certain you only want the alk part, but I would generally dose both parts unless calcium is already too high.

CindyKz · Oct 14, 2017

Randy Holmes-Farley said:
Let's put that calcium rise in perspective lol

It will not "jack the Ca way up".

You are asking about raising calcium from 6.5 to 8.1 dKH. A rise of 1.6 dKH.

A perfectly made two part dosed in equal parts for that rise will boost calcium by about 11 ppm.

So if you are perfect at 420, it becomes 431 ppm, which is still perfect, and probably not even a difference you can accurately measure.

Yes, you can dose just the alk part if you are certain you only want the alk part, but I would generally dose both parts unless calcium is already too high.

Randy, can you please tell what you would consider " too high" in this instance?

Randy Holmes-Farley · Oct 14, 2017

CindyKz said:
Randy, can you please tell what you would consider " too high" in this instance?

More than 500 ppm, I'd stop dosing any calcium. More than 550 ppm and I'd be looking at ways to slowly reduce it (like water changes).

CindyKz · Oct 14, 2017

Randy Holmes-Farley said:
More than 500 ppm, I'd stop dosing any calcium. More than 550 ppm and I'd be looking at ways to slowly reduce it (like water changes).

Thank you

Randy Holmes-Farley · Oct 14, 2017

You're welcome.

Happy reefing.

cracker · Oct 14, 2017

Thanks Man ! I was fairly sure I needed to add the Ca as well. I have read an article by You I think saying why it's important to dose both when using a "balanced" 2 prt. I'm using Ocean's Blend.

cracker · Oct 17, 2017

I have a mystery on my hands. 1st the mystery, It appears that the Alk went from 8.0 to 6.9 in 2 days !
A brief history, I recently purchases a Hanna Alk checker. I did this because a test using older (not expired for a year) regent did not agree with a new bottle of regent. The old regent gave me a much higher reading than the new. This is a Red Sea pro kit. I always wanted to check out Hanna testers & needed something to compare the red Sea tests to. Anyway sure enough the new red Sea & Hanna were very close. The old kit was giving me a false high reading. The old said 8.0 the 2 new kits gave me a 7.0 . Over the weekend I slowly dose my Ocean's blend using equal amounts based on the alk. I got it up to 8.0 Sunday eve.
Tonight I was bored & tested the alk again with the new Hanna & got a 6.9 reading ! I'm thinking this can't be right so I carefully repeated the test. got the same again. Then I used the new Redsea & this test agreed !
So how did the alk drop from 8.0 to 6.9 in 24 hours? I haven't done anything to the tank.
I'm not freaking out just frustrated. This is why I love this hobby if that's what You could call it . Sometimes it seems to be so much more. I also hope somebody picks this up as it is a change in the topic. If this is the case I will start another thread & repost. Thanks.

Randy Holmes-Farley · Oct 18, 2017

Alk can easily drop 1.1 dKH in a day. It can drop several times that fast.

cracker · Oct 18, 2017

Well Thanks again . So I will dose it again to 8.1 alk & adding equal amounts of the 2 prt . I have been working on keeping levels stable. It's my 75 gl coral experiment tank. It's a little over 2 years old . I always had a steady but slow drop of alk but never this fast . There are a little over 20 corals . Some softies mostly lps & 2 sps . I used fully saturated kalkwasser thru the ato. I don't get it why this tank requires so much alk. However I will keep up the good fight !
Randy , You are a true guide down the path of knowledge !

Randy Holmes-Farley · Oct 18, 2017

Alk demand doesn't usually pop up and down, but there's no reason to not boost it and keep watching. It could be demand has increased, or that slight testing errors explain it (a little high the day before and a little low the second day will show a bigger than real demand). That's why long term monitoring is useful.