View Full Version : Having trouble trying to dial in my dosing.

09/07/2017, 08:12 PM
Well I hope this is an easy question.
120 gallon tank
30 or so gallon dump
Apex dos

I recently switched from dosing calcium and alk to kalkwasser to help with my ph.


Ph - 8.14/8.23 apex
Alk - 8.5 Hanna
Calc. - 420 Red Sea
Mag. - 1320 Red Sea

I was trying to get my alk up to 9.5/10. So I mixed up some brightwell buffer powder as directed and since I don't know my exact gallons of my tank I guessed at about 130. So I added the 85 ml to supposably get my alk to just about 10. Well I'm guessing my gallons of water was of because I tested the water a half hour later and it was 11.05. So I decided to leave it and see how far it dropped over the next day. Well I tested 23 hours later and my alk read 8.5. This doesn't seem right to me. I have never had this much fluctuation in one day.

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09/07/2017, 09:53 PM
How much Kalkwasser is going into the system? That alkalinity drop is large. It's possible that it dropped that much. My soft coral tanks went through 2-3 dKH per day, but they had a lot of coralline algae growth.

09/08/2017, 04:42 AM
I do 4000ml a day will fully saturated water. The reason it seems off to me is I have done this test before when I got my doser so I could figure out my amounts to dose and wasn't nearly that big of a drop. If I remember correctly it was maybe 0.3 per day.

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09/08/2017, 02:22 PM
That's a fairly large dose, maybe 1.5 dKH in limewater going into the system. I'm not sure what's happening, but I'd dose the alkalinity up and watch the consumption rate for a few days. What animals are in the system? Is there a lot of coralline growth?

09/08/2017, 02:26 PM
Yellow tang, yellow wrasse, clown, Mandarin dragonette. 25 or so headed frogspawn and some small sps and lps. Not a lot of coralline.

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09/08/2017, 02:30 PM
I have to admit that I have really always had issues with figuring out dosages and applying them. I always read about keeping things so stable but for me i can't seem to find that sweet spot. If I do come upon that stage were everything seems to be going really well it doesn't last.

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09/08/2017, 03:38 PM
Hmm, I am not sure what is consuming the alkalinity, so I'd watch for signs of precipitation. I think that measuring alkalinity and dosing every day should get you a trend line. You might want to measure the alkalinity before dosing and maybe 10 minutes afterwards for a bit, to help tune your estimate of the volume of the water column.

09/13/2017, 09:49 AM
I'd say go back to dosing alkalinity instead of kalk. And I agree with Bertoni, try to get a better estimate of alk consumption per day by removing dosing and measuring the alk levels for a few days, then average the drops. Another point was to re-estimate the water volume in your system. This always seems to be an overestimate... a 300 gallon tank is never going to hold 300 gallons of water, especially if there is any kind of rock work, etc. My own tank is a 300 with a 60 gal sump (50% full) and a 40 gal refugium (30 gal). When I calculate dosing for my tank, I use an estimate of only 300-310 gallons in the system versus the 360 I showed earlier. This seems to be just about right based on my dosing and testing.

09/13/2017, 10:51 AM
Well the reason I started dosing kalk was I have been have bad ph issues and this is the one thing that seems to actually help.

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09/13/2017, 03:59 PM
Kalk should be fine to use. Just to be clear, the dose is always 4000 ml per day? It's not hooked to ATO? I'd just keep up with the daily measurement and dosing for a while to get a trend line.

09/13/2017, 04:32 PM
Yes, 4000 a day and then I have a separate ATO with just RO.

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09/14/2017, 02:21 PM
Try using this to see how much alk you are adding.

Saturated line water adds about .95 dKH per gallon added in a 130 gallon system.