Help with dosing problem.

[Randy Holmes-Farley]

If the value is correct now, then it likely wasn't before.

How many days are we talking about between readings?

 

[AJI23]

3.5 days. Was tested Sunday at 10:30 am. By myself and lfs. Then tested again last night wendsday at 8:00pm. Almost 4days.

 

[Randy Holmes-Farley]

SO there's no chance the tank used 110 ppm of calcium in 4 days without adding large amounts of alkalinity. That is likely testing error. Don't agonize looking for other explanations.

 

[AJI23]

Well I added the dosage that the brs calculated last night and tested inbetween a few doses and got my calcium up to 420. My alk was at 9. I will test as soon as I get home. Which will be in a hour or so and retest. I have turned off all dosing pumps. Last night. So I haven't added any solution in 24hrs. And will continue to leave off till Saturday. To see how much I am consuming. I will post my reading results in alittle while.

 

[AJI23]

Well randy you are absolutely right. I have been heavily dosing all at 528 mls a day. But have now stopes. And calcium was dosing. 465mls a day. So the abundance of alk is dropping my calcium.

 

[AJI23]

Ok calcium is at 410 and alk is at 6.3 dkh. Calcium dropped 10ppm and alk dropped 2.7 dkh In 24 hrs.

 

[Randy Holmes-Farley]

Within your ability to measure calcium, that's not unreasonable. The exact ratio used is probably ~18-20 ppm calcium for each 2.8 dKH of alkalinity.

 

[AJI23]

Ok so second day without dosing and my levels dropped to 5.6 dkh and 390ppm calcium. That's 20ppm and 0.7 drop in dkh.

 

[Randy Holmes-Farley]

Alk and calcium will stop declining about now as it is getting hard for corals to calcify with alk that low. I would restart some dosing.

 

[AJI23]

At what dosing rate.

 

[Randy Holmes-Farley]

I'd start at equal parts, equivalent to 1 dKH per day and see what that accomplishes after several days.

This calculator may help determine the amount:

http://reef.diesyst.com/chemcalc/chem_calc3.html

 

[AJI23]

Hi. I'm still having a problem with my dosing. I am setting it at 120mls a day per alk and cal. My cal is good staying at 420 but my alk won't go above 6.7, 6.4. I've added the recommended dosage as per brs calculator and after a hour I test and it's like I never added anything. I don't want to keep adding alk. Another ? Is if I add alk should I also add calcium equal part. Will One effect the other. Ex: add cal lowers alk. Add alk lowers calcium. How do I get my levels where I want them then dose from there.

 

[Randy Holmes-Farley]

By recommended dosage, you mean the amount to get to 1 dKH added per day?

If that has been added a few days and alk is still lower than you want, let's up it to 1.5 dKH for a few days. The idea is to use the minimum dose needed to get to an alk you are happy with.

That said, if you are at 7 dKH and add enough to reach 8 dKH, I'd be surprised it it really is back to 7 dKH in 1 hour. Try measuring at a shorter time, and maybe spread the dosing out over the day a bit.

 

[AJI23]

The problem that I am having is that I want my alk at 8-9 dkh and cal 420-430. So my calcium is where I like it but my alk is not. It's staying at 6.5ish. Brs recommends about 220 mls to bring that level up to 9. I slowly added 220 mls over about 10 mins. I check it a few hours later(2-3hrs). And it's at 7.2-7.4.

I want to set my levels at alk 9 and Ca 430. But for some reason I can't get them to balance out at these numbers without having to add massive amount of solution.

 

[AJI23]

So it appears that I am still precipitating. Came home and found a white film all over my display and sump glass. Should I lower my tank temp from 79.5 to 78. Will this help.

 

[Randy Holmes-Farley]

I'd double check that the alk kit is reading correctly.

I'd also add the alk spread over more of the day. Like some AM some PM.

 

[AJI23]

Alk still staying at 6.4. Calcium is 400

 

[hutch2828]

Check your magnesium. I've always heard it's what allows higher than nsw levels of Calc and alk.

 

[AJI23]

Mag is at 1500 A little high. But not the problem.

 

[Randy Holmes-Farley]

Switching to baking soda(sodium bicarbonate) as an alkalinity supplement will likely reduce precipitation relative to using washing soda (sodium carbonate).