Help - Alk dosing seems off

mitch91175 · May 30, 2019

Here is a graph showing my pH:

Here is what my schedule looks like for dosing kalk:

I will say that as long as my pH was below 8 I did not get the consumption that I have now. Running a CO2 scrubber as well so unless there is something that I am doing to the system that will drop the pH for more dKH consumption, it has been averaging around 8.2 and I have 100% noticed increase in consumption and growth.

The way I run my tank isn't for everyone for sure. Running CaRx, kalk stirrer, and have Alkatronic dosing dKH when necessary. I feel and see that doing all of those things in my system that it has been extremely beneficial.

madweazl · May 30, 2019

First off, don't get too caught up in a measured change of .2 dKh as your test kit lacks the resolution to accurately test for deltas that small. Even if the delta is .2 dKh, that isn't enough to be of any concern. A lot of people like to test alkalinity daily but it's largely unnecessary, especially in a low demand system (what you have). I'm not a fan of keeping higher alkalinity levels but many do; if the oceans typically run about 7 dKh, it stands to reason that your best results are going to be in the same range (I'm not one to mess with millions of years of evolution).

Your salt mix has high levels of calcium so your measured results of 500+ are expected. If you haven't measured freshly mixed Reef Crystals, try it so you know what you're adding to the tank (check the alkalinity as well). I think a lot of people confuse the consumption rates of alkalinity and calcium with the dosing rates. If your calcium exceeds your desired levels, there is absolutely no reason to dose it (same goes for alkalinity).

With a consumption rate of .1 dKh per day, I wouldn't even bother dosing anything because your water changes are likely enough to reasonably keep up with demand at this point; you'll only need a small, weekly correction to get back to desired levels (if anything at all). Go an entire week without testing your alkalinity (nothing is going to die) and then see where it's at. Make your decision off of that result.

JCOLE · May 30, 2019

Ron Reefman said:
This was exactly what I was thinking. Back off and let the tank do it's own thing. But keep a close eye on water parameters and do some water changes.

One other point, don't worry about; and absolutely don't chase pH levels unless they get down in the 7.6 range and stay there. Then fix it by better gas exchange with the air at the water surface (waves and motion) or by bringing in outside air to your skimmer. Trying to do it with soda ash or any other chemical treatment is extremely temporary (as in hours at best).

Will do. I will let it ride for a couple weeks ago and check back in. Thanks for the help!

JCOLE · May 30, 2019

mitch91175 said:
I'd say just stop dosing and do water changes, but still check you levels daily. Do not dose anything until you understand the trends with your tank. Having the levels drop during the week isn't an issue as long as they are dropping through the floor. If that happens while testing, then dose to make up the difference.

If you really want to grow SPS fast and have more consumption, increase your pH to average higher than 8. Once you get the pH higher, you will definitely notice dKH consumption. Not saying chase pH by dosing dKH either. You were likely better off just continuing to use your kalk instead of switching. If you are having a large dKH consumption per day, then look into adding to what you are already doing. Only you can determine what that number is for you situation.

The key will be knowing when you have growth spurts and dosing at those times. It's gonna be a challenge getting to that point but it is worth it once you do.

Will do. I am going to hold off for a couple weeks. Hopefully my levels drop to around 8.3-8.4. That is where my LPS seemed to look really good and happy. Once it hits that then I will start off with a little dose of kalk in my ATO for starts.

JCOLE · May 30, 2019

madweazl said:
First off, don't get too caught up in a measured change of .2 dKh as your test kit lacks the resolution to accurately test for deltas that small. Even if the delta is .2 dKh, that isn't enough to be of any concern. A lot of people like to test alkalinity daily but it's largely unnecessary, especially in a low demand system (what you have). I'm not a fan of keeping higher alkalinity levels but many do; if the oceans typically run about 7 dKh, it stands to reason that your best results are going to be in the same range (I'm not one to mess with millions of years of evolution).

Your salt mix has high levels of calcium so your measured results of 500+ are expected. If you haven't measured freshly mixed Reef Crystals, try it so you know what you're adding to the tank (check the alkalinity as well). I think a lot of people confuse the consumption rates of alkalinity and calcium with the dosing rates. If your calcium exceeds your desired levels, there is absolutely no reason to dose it (same goes for alkalinity).

With a consumption rate of .1 dKh per day, I wouldn't even bother dosing anything because your water changes are likely enough to reasonably keep up with demand at this point; you'll only need a small, weekly correction to get back to desired levels (if anything at all). Go an entire week without testing your alkalinity (nothing is going to die) and then see where it's at. Make your decision off of that result.

If I am dropping my ALK .10 everyday and I dose say 1 dKh once a week then wont that stress the corals with a big swing in ALK?

Also, I might need to change salt brands also if my ALK and Calcium are elevated in this brand. If my Alk remains around 8.3 and I do a water change with a salt that has high 9's or higher then that will cause a big swing as well, Correct?

madweazl · May 30, 2019

h2oh2o said:
If I am dropping my ALK .10 everyday and I dose say 1 dKh once a week then wont that stress the corals with a big swing in ALK?

Also, I might need to change salt brands also if my ALK and Calcium are elevated in this brand. If my Alk remains around 8.3 and I do a water change with a salt that has high 9's or higher then that will cause a big swing as well, Correct?

If everything else is good in your tank now, the 1 dKh change wont cause any problems. A 15% water change using Reef Crystals (usually mixes up around 10.5-10.7 dKh) will increase your alkalinity but not by an amount that would be harmful (increase should be <= .3 dKh). Your alkalinity doesn't have to stay right on the money all day every day, eliminating drastic changes is the real objective. If your alkalinity dropped by .1 dKh/day for 20 days from 9.0 to 7.0 (just an example), the corals wouldn't show any stress (provided there weren't other issues occurring). With your example, if it dropped .1 each day and you did a one time correction of .7 dKh seven days later, there wouldn't be an issue. I'm not advising to encourage fluctuations, just re-iterating that changes to alkalinity levels arent nearly as destructive as some would have you believe.

I typically maintain an alkalinity around 7 dKh and I travel a lot. Even though my setup is on dosing pumps, I'll still have growth spurts that increase demand while I'm away. Last year, after about two weeks out of town, my tank dropped down to roughly 5.5 dKh and everything looked great. I bumped the dosing up a bit and brought it back up to 7 dKh over the course of the next week or so but I could have a done a couple larger dose corrections to get it back in line in a few days. I wouldn't hesitate to increase alkalinity by 1 dKh in a single dose (I've done considerably more than that on occasion).

mitch91175 · May 30, 2019

Here is a good video about using kalk with your system when that time comes:

Ron Reefman · May 31, 2019

h2oh2o said:
If I am dropping my ALK .10 everyday and I dose say 1 dKh once a week then wont that stress the corals with a big swing in ALK?

Also, I might need to change salt brands also if my ALK and Calcium are elevated in this brand. If my Alk remains around 8.3 and I do a water change with a salt that has high 9's or higher then that will cause a big swing as well, Correct?

That's a big fat NO! Yes, everybody will stress keeping water parameters stable, but that's only true up to a point.

I have a 40g cube stuffed full of zoas and RFA's along with a few lps and sps corals. I one week my alk goes from 10.0 dKH down to 6.0 or 7.0 dKH and I dose it back up to 10.0 dKH manually by dosing myself every 15 minutes over 60 to 90 minutes, depending on my schedule that day. So a 3.0 to a 4.0 bump in alk over an hour. And how do my sps and lps deal with it? You wouldn't even know I dosed anything, they are all open, colorful and growing.

Now even I think that big a swing is risky despite evidence to the contrary in my tank. So now I'm dosing 2 or 3 times a week instead. That keeps the alk swing down to about 1.0 dKH. I consider that a small swing in my tank.

JCOLE · May 31, 2019

I think I need to chalk this up to my phosphates. My phosphates were around .36-.46 the last week or so. I put in a media reactor with Phosguard Wednesday night. Yesterday afternoon everything was looking better. My GSP was back out and the LPS looked fuller and not stressed. Going to run Phosguard for a couple days to see how everything looks.

Randy Holmes-Farley · Jun 2, 2019

h2oh2o said:
If I am dropping my ALK .10 everyday and I dose say 1 dKh once a week then wont that stress the corals with a big swing in ALK?

Also, I might need to change salt brands also if my ALK and Calcium are elevated in this brand. If my Alk remains around 8.3 and I do a water change with a salt that has high 9's or higher then that will cause a big swing as well, Correct?

Not if you do a 10% water change. A tank at 8.3 dKH that does a 10% water change with 10 dKH water only jumps to 8.47 dKH.