alk dosing question

[jokersplayground]

Ok so I have figured out that my alk drops .7 in 2 days. By this I mean I dose to bring up it from 7.0 to 7.7. I wait 24hrs to test and I get that I reached my goal. So then I wait another 24 hours to test again and it drops to 7.0. Now my question is is this a good number for it to be dropping within 2 days? Am I doing this dosing thing right?

 

[wolffman1992]

Alk will drop in the aquaria due to coral uptake so it means your corals are using the Alk up. Calcium will drop all and alk will drop calcium. You want to dose equal parts until you reach your desired levels. You should dose everyday to minimize swings. Swings of 1 dkh can cause issues. .7 is close to 1.

 

[jokersplayground]

So I would have to test twice in one day to see how much it has dropped. What if it has not dropped at all?

 

[JohnK]

More like you work out a steady dose over time so that you know how much supplement you need to add daily. For example, lets say you are currently adding 10 ml every two days - so make that 5 ml every day and that daily dose should be about right. Test in a couple of days and if your level has dropped below your target level then up the daily dose to 6 or 7 ml per day. Eventually you should get to a point where you will be adding a steady dose every day, and you can test weekly or so.

 

[jokersplayground]

Ok so in order for me to get from 7.0 to 7.7 I need to dose 55 ml of brs sodium bicarbonate alk solution. So I would just split that in half and dose it over the 2 day. I will try this after 2 days are up as I just dosed the 55ml today.

 

[JohnK]

Basically yes. Currently you are adding 55 ml and 24 hours later the alk tests at 7.7, and another 24 hours later it tests at 7.0. This really means that your tank is using about 27.5 ml per day, (If you tested a couple of hours after adding the 55 ml I'll bet it tests closer to 8.4). So if you start dosing 27.5 ml per day the level will stay more steady. Your tank's consumption will be about the same every day (but slowly increasing over weeks and months as your corals grow larger) so you can stick with that daily dose and not worry about testing every day. Over time you will likely see the level start to drop slightly when you do test, then you increase your daily dose slightly until you see the level holding steady again.

 

[JohnK]

Basically yes. Currently you are adding 55 ml and 24 hours later the alk tests at 7.7, and another 24 hours later it tests at 7.0. This really means that your tank is using about 27.5 ml per day, (If you tested a couple of hours after adding the 55 ml I'll bet it tests closer to 8.4). So if you start dosing 27.5 ml per day the level will stay more steady. Your tank's consumption will be about the same every day (but slowly increasing over weeks and months as your corals grow larger) so you can stick with that daily dose and not worry about testing every day. Over time you will likely see the level start to drop slightly when you do test, then you increase your daily dose slightly until you see the level holding steady again.

Also be aware that, like wolfman said, Ca will be being consumed at the same time. Typically if you are using 2 part additive, the amount of the additives will be the same so you should be adding the same 27.5 ml of Ca to go along with the alk (you won't see the Ca seem to drop as quickly but don't worry about that - they did the math when they figured out the 2 part recipe).

You can use the reef chemistry calculator to predict the doses if you are not already sure; http://reef.diesyst.com/chemcalc/chemcalc.html

 

[jokersplayground]

Also be aware that, like wolfman said, Ca will be being consumed at the same time. Typically if you are using 2 part additive, the amount of the additives will be the same so you should be adding the same 27.5 ml of Ca to go along with the alk (you won't see the Ca seem to drop as quickly but don't worry about that - they did the math when they figured out the 2 part recipe).

You can use the reef chemistry calculator to predict the doses if you are not already sure; http://reef.diesyst.com/chemcalc/chemcalc.html

the thing with my calcium is that it stay solid at 480. I do weekly water changes and it stays at that level. its just my alk that drops.

 

[JohnK]

sounds like your salt runs high in Ca. If the water changes keep up with the Ca, then don't worry about it.

 

[jokersplayground]

sounds like your salt runs high in Ca. If the water changes keep up with the Ca, then don't worry about it.

Ok thanks john

 

[this is me]

Now my question is is this a good number for it to be dropping within 2 days?

I don't think you understand the concept of corals intake of ALK, CA, MG, and anything else in the water.
How can you even control how much your tank is consuming? The bottom line is, it doesn't matter what this number is in your tank vs. others. You just need to keep up.

 

[letoan]

What's your mag level? IME, it's easier to maintain the big 3 is keep them in balance to each other and not chasing any number.