Calculating initial dosing

Jonathan Schor · Aug 14, 2017

I need a little help in calculating initial dosing for components 1,2,3

I have a 40 gallon tank with 15 gallon sump. I do bi weekly water changes. The initial numbers after water change are:
KH-7.45 Ca-431 Mg-1250

1 week later
KH-7.34 Mg-1300

1 week after
KH-6.84 Ca-397 Mg-1250

What should my initial dose be? Need a little help.

Thanks

120reefkeeper · Aug 14, 2017

Jonathan Schor said:
I need a little help in calculating initial dosing for components 1,2,3

I have a 40 gallon tank with 15 gallon sump. I do bi weekly water changes. The initial numbers after water change are:
KH-7.45 Ca-431 Mg-1250

1 week later
KH-7.34 Mg-1300

1 week after
KH-6.84 Ca-397 Mg-1250

What should my initial dose be? Need a little help.

Thanks

So we're all these numbers taken 2 weeks apart??

You said you do biweekly water changes. From my quick math if you increase your water change frequency then you'll meet your current demand without dosing at this point.

If you insist on dosing then it would be very very minimal. Approx 1 to 2 ml of each product per day. At this point I would just do weekly water changes until that no longer meets the demand. [emoji4]

Jonathan Schor · Aug 14, 2017

No the numbers are weekly.

The first number was after regular weekly water changes for 3 months. Then I checked chems weekly. When I saw the low KH, after week 2, I did a water change to get the numbers up. I'll plan on another set of chems tonight.

Also, My goal is to stop doing weekly water changes. Its a time consuming and labor intensive part of the hobby. I think that if I can keep the numbers stable over 2-3 weeks it would reduce the need for frequent water changes.

120reefkeeper · Aug 14, 2017

Jonathan Schor said:
No the numbers are weekly.

The first number was after regular weekly water changes for 3 months. Then I checked chems weekly. When I saw the low KH, after week 2, I did a water change to get the numbers up. I'll plan on another set of chems tonight.

Also, My goal is to stop doing weekly water changes. Its a time consuming and labor intensive part of the hobby. I think that if I can keep the numbers stable over 2-3 weeks it would reduce the need for frequent water changes.

Everyone has a different philosophy when it comes to water changes. I still believe in weekly 10% changes. This doesn't mean there is anything wrong with doing biweekly, it can be done with great success.

At this time I think your dosing is going to be very minimal. So what I would do is test test test. Check your Alkalinity daily at the same time each day. See what your daily consumption is and then set up your dosing according to your daily Alkalinity consumption. The other components 1&3 will be dosed in equal amounts to the amount of component 2 you use.

Jonathan Schor · Aug 14, 2017

If that's the case at what point would you consider dosing? If the alk drops by 1 point a week? What would be your threshold to start? I thought that the idea is to maintain stability over the week.

120reefkeeper · Aug 14, 2017

Jonathan Schor said:
If that's the case at what point would you consider dosing? If the alk drops by 1 point a week? What would be your threshold to start? I thought that the idea is to maintain stability over the week.

Oh I agree stability is key. In my humble opinion when you see a 0.2 dkh drop per 24 hours you need to get the doser ready. So if you figure that out that would be about 1.4 dkh per week if left unchecked. Until then you can either do more frequent water changes.... weekly.... or just hand dose every few days . If I did nothing with my display tank I would loose about 2.6dkh per day.