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Old 06/13/2018, 06:25 AM   #1
cedwards04
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How do you know when it is time to start dosing?

I am new to reef tanks. My tank has been cycled and stocked since march. I know everyone says keep parameters stable and big swings are not good, but what exactly is concidered a "big" swing? I am using red sea coral pro salt and finding that my alk is dropping rapidly while my ca seems to be staying fairly consistent.

For example. Doing weekly water changes of 20%, my ca is staying between 420-440, while my dkh is reading 9.5 down to 6.5 before my next waterchange. I feel like i should be dosing alk.

Mg is almost always exactly the same reading every [email protected]

Tank is 50/50 mix of sps frags and lps.

Sg 1.026
Nitrates 0
Dont have a phosphate test kit yet.

I am using red sea test kits.


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Old 06/13/2018, 06:32 AM   #2
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Itís time to start dosing.

You want your alk to stay pretty stable through the days.

If youíre dropping from 9-6 dKH, thatís a huge swing. I test daily and I drop from 9 to 8.6 pretty much over night.

I would go straight to two part. Itís simple as it comes. Kalkwasser is a good alternative, but I didnít want to destroy my ATO pump.


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Old 06/13/2018, 07:16 AM   #3
cedwards04
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So how much daily swing is acceptable? I'll start looking into dosing pumps. Im not into having to manually do it daily haha. Plus i work out if town a lot so it needs to be somewhat automated to work at least a few days on its own.


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Old 06/13/2018, 08:17 AM   #4
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I'm skeptical of your results unless you just threw a crap ton of hard corals into the tank...
I would most certainly not expect a drop of 3dkh a week in a "new" tank.. but I have no idea how many corals you really have..
Some heavily stocked tanks can consume 2dkh or more daily..
But the fact that you cal is not dropping is part of my skepticism.. Usually both are consumed equally (or fairly close to that..) Its not uncommon at all for people to need to dose more alk than cal solution but needing to dose 3dkh a week and zero cal is a little "fishy"..

In general the max recommended daily swing is like .5-1dKH... anymore and you run into problems.. Typically swinging up is more harmful than swinging down...

But yes.. you know when to dose when your current water change schedule/amount isn't sufficient to keep levels "stable" and you don't want to increase that schedule or amount to compensate.. At that point you look into dosing.. Plain and simple..


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Old 06/13/2018, 08:44 AM   #5
cedwards04
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I'm skeptical of your results unless you just threw a crap ton of hard corals into the tank...
I would most certainly not expect a drop of 3dkh a week in a "new" tank.. but I have no idea how many corals you really have..
Some heavily stocked tanks can consume 2dkh or more daily..
But the fact that you cal is not dropping is part of my skepticism.. Usually both are consumed equally (or fairly close to that..) Its not uncommon at all for people to need to dose more alk than cal solution but needing to dose 3dkh a week and zero cal is a little "fishy"..

In general the max recommended daily swing is like .5-1dKH... anymore and you run into problems.. Typically swinging up is more harmful than swinging down...

But yes.. you know when to dose when your current water change schedule/amount isn't sufficient to keep levels "stable" and you don't want to increase that schedule or amount to compensate.. At that point you look into dosing.. Plain and simple..
Funny you should mention being skeptical, i had that same discussion with the wife last night. I am finding it hard to believe my results as well, but being new to the hobby i just wasnt sure. I have 50 gallons of total water volume in my setup (40 breeder/20 long sump). I currently have 3 hammer corals about tennisball size, 3 acan's (1 has around 10 heads, 1 has 5 heads, 1 has 2 heads) i have an octospawn that is only about 3 inches tall. I have 7 sps frags, 3 are about 1.5", another 3 are about 5" tall, one is a plating coral about 2". I cant upload pics from my phone or i would post a picture. Not sure if that helps. I am going off of results from 2 weeks. Admittedly i wasnt testing like i should have prior to that. I plan to test every 2 days this week rather than waiting a whole week.


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Old 06/13/2018, 08:54 AM   #6
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Ok.. so 3dkh in 2 weeks is more believable given the corals you state you have..

You can certainly test every 2 days.. Just make sure to record when you are doing water changes also so we can see how your levels are with that in the equation..
Then come back in 2 weeks with all that data and we should see a clear trend.. I'd recommend testing before a water change and then a few hours after one too each time you do that water change..

I'm not sure if you just have 1 test result so far but lets not react on a single data point...

You do have "some" corals.. Not heavily stocked by any means and I'd guess that 20% every week "should" be close to keeping you stable.. But lets get multiple data points/test results to see..


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Old 06/13/2018, 09:36 AM   #7
cedwards04
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So to be clear, i have collected data over 2 weeks time. I originally started out with 10% weekly water changes bc i did not have many corals. After adding several pieces i decided it was time to start testing to be sure 10% was enough. To start my data collection, i do waterchanges every monday evening. I tested on tuesday evening, 1 day after my waterchange. I tested again on monday right before my waterchange. I try to do all my testing during the same time of day. I have everything written down in a notebook at home so i will have to post all those results later bc i dont remember all of the numbers for each test.

I do remember my first test to start the process resulted in 7.0dkh, which i thought seemed pretty low. I also tested my freshly mixed water at 13dkh if memory serves correctly (red sea coral pro).
Ca was 440, i dont remember the number on the fresh mix.

I did a 20% waterchange, and tested again on tuesday evening. 9.5dkh, cant remember ca.

The following monday i tested again before my waterchange
6.8dkh
Ca 420

Did another 20% waterchange. Waited a week and tested again before my waterchange this Monday
6.5 dkh
Ca 420.

I have everything written down at home, right now im at work and going off memory which isnt grest haha.

I tested last night, 1 day after my last 20% waterchange and got 7.8dkh. I didnt have time to test ca last night but i did pull a sample and place it in a airtight container so that i can test it later.

I have tried hard to be very consistent and exact when measuring out the water to be tested, but i sometimes wonder if the test is accurate. A few times i have repeated the test to be sure my results are consistent, and they are.

I am now on week 3 of testing and will test every other day to try and get the most accurate data i can get.


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Old 06/13/2018, 09:40 AM   #8
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I feel like my results dont make sense, but i have performed the tests multiple times to be sure im getting accurste results. My consumption doesnt appear to be linear, and i feel like it probably should be. So im skeptical of trusting my results. Im tempted to buy some hanna checkers and compare.


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Old 06/13/2018, 03:27 PM   #9
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Quote:
Originally Posted by cedwards04 View Post
I feel like my results dont make sense, but i have performed the tests multiple times to be sure im getting accurste results. My consumption doesnt appear to be linear, and i feel like it probably should be. So im skeptical of trusting my results. Im tempted to buy some hanna checkers and compare.


Do it.

I think I am color blind (Iím a male, so itís likely) so the color changing is tough for me to see if it changes from pink to blue (ala Red Sea). I am using Hanna alk and I love it. Heard calcium is not accurate. Next month on payday Iím going to buy a phosphate test kit too.

Love them and the refills are cheap! $8!


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Old 06/13/2018, 03:57 PM   #10
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Originally Posted by cedwards04 View Post

I do remember my first test to start the process resulted in 7.0dkh, which i thought seemed pretty low. I also tested my freshly mixed water at 13dkh if memory serves correctly (red sea coral pro).
Ca was 440, i dont remember the number on the fresh mix.

I did a 20% waterchange, and tested again on tuesday evening. 9.5dkh, cant remember ca.

This right here tells me you have an error in your testing. There is no way(even if your NSW was 14DKH) that you could raise your ALK 2.5 DKH with a 20% WC. The math just doesn't add up.



Same here as above poster. Not color blind, but could never get consistent results with Red Sea kits. Switched to salifert and got more consistent results. Switched to a Hanna checker just for relative ease of use since ALK will be the one kit you test the most. Besides who wouldn't agree that a numerical readout is better then trying to judge a color change?


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Old 06/13/2018, 09:15 PM   #11
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Also. Am I wrong everyone in asking what the Mag. Level is. With strange, unstable results(think this particular case is a testing error) Mag. May be way off and result chasing?
Dumb question, how are you administering the Red Sea titration process? I know back when I first used them it was a bit confusing with the amount of titrator in the syringe and how to measure your readings. I'm thinking this and or just user error may have both occured. All the info others are providing is right on point though.

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Old 06/13/2018, 10:32 PM   #12
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A very low magnesium level could cause a lot of extra calcium and alkalinity consumption, but that's extremely rare. There's nothing in your results that makes me think a new magnesium kit is worth getting, but if you're very worried, it wouldn't hurt to get a result. I suspect that you are seeing testing problems or limitations, which is a very common issue.

A drop of 3 dKH (from 9.5 dKH to 6.5 dKH) corresponds to about a 22 ppm drop in calcium, which is close to our testing limits. There are some processes that will consume alkalinity but not calcium, though:

http://reefkeeping.com/issues/2004-12/rhf/index.htm

The Hanna alkalinity meter might be a good investment if you are having trouble detecting color changes. Personally, I think that the consumption rate is low, which makes our test kits a bit marginal in dealing with changes in calcium level. I'd get a 2-part, or make one, and dose according to the alkalinity test results, and see how that goes.


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Old 06/14/2018, 06:24 AM   #13
cedwards04
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So last night i tested some water i had previously placed in a water tight container from tuesday. On tuesday i got a reading of 7.8dkh. Testing that same water sample again last night, i got a reading of 10dkh. This tells me i am absolutely doing something wrong, or my test kit is bad (most likely user error).

At this point i have decided i cannot trust my collected data, and i cannot trust myself using the red sea kit. I went ahead and ordered the hanna checker dkh and calcium kits. I also ordered the specific hanna water for the ca checker due to reading reviews of people saying they are not accurate without using it. I will re start testing once everything arrives in a few days.

Mg has never changed at all in any of my tests, it has always read pretty high at 1420.


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Old 06/14/2018, 07:38 AM   #14
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This right here tells me you have an error in your testing. There is no way(even if your NSW was 14DKH) that you could raise your ALK 2.5 DKH with a 20% WC. The math just doesn't add up.



Same here as above poster. Not color blind, but could never get consistent results with Red Sea kits. Switched to salifert and got more consistent results. Switched to a Hanna checker just for relative ease of use since ALK will be the one kit you test the most. Besides who wouldn't agree that a numerical readout is better then trying to judge a color change?
I also use the salfert test kits. I find it is easiest to do the test in front of a window. Much easier to see the color change for me. Though my neighbors must think I might be cooking meth watching me drip and swirl once a week.


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Old 06/14/2018, 11:03 AM   #15
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So last night i tested some water i had previously placed in a water tight container from tuesday. On tuesday i got a reading of 7.8dkh. Testing that same water sample again last night, i got a reading of 10dkh.
I agree that that must be a testing error.

I am sorry to hear about your problems with the test kit. Please let us know how the Hanna works for you! More reviews always are welcome.


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Old 06/15/2018, 07:50 PM   #16
cedwards04
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ok, so now that i am home and looking at my log book, i realize my memory was pretty off haha. here are my actual test results.

initial test:
ca 440
dkh 7.0
mg 1420

after 7 days:
ca 420
dkh 6.4
mg 1420

insert 20% water change, waited 1 week, retested
ca 450
dkh 7.4
mg 1420

i went ahead and tested dkh only again tonight. i ran the test 3 times to ensure accurate results, all 3 tests were within 0.1dkh of each other. i also retested a water sample i had left from the last time to be sure the dkh reading was accurate then, and got a reading of 7.3 dkh, so within 0.1 again. i think i just screwed up that one test that read crazy high somehow and i am going to disregard it.

so tonights test results are 7.0 dkh. i tested 3 times to be sure it was correct. this means i have lost 0.3-0.4dkh in a few hours shy of 4 days time.

by my math from my data collected so far, i am consuming approximately 0.1dkh/24hr period. i also did the math on how far a 20% water [email protected] should swing my water, and it works out very close to my test results.

i am going to continue to monitor my water using the red sea kit until my hanna checkers arrive. at that point i will begin testing using both until i decide which one i feel to be most accurate.

my biggest question at this time is how much of a daily or weekly swing is too much? i am sure the ultimate goal is for there to be virtually no swing, but realistically, how much can it swing before i start experiencing side affects from it? i am trying to determine if i need to start dosing.

i have done the math and at my current tested consumption rate, a 20% waterchange is going to raise my dkh each week by approximately 0.3-0.4 as i am putting more back in at the moment than is being consumed. but again, i know that stability is best so am i over compensating with a waterchange when i should be dosing?


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Old 06/15/2018, 11:30 PM   #17
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That's a very low consumption rate. My soft coral tanks went through 2-3 dKH per day due to coralline growth.

How much of a swing the corals will tolerate probably depends on the species involved. Soft corals won't care. Some people claim 1 dKH is an upper limit for their corals. I wouldn't worry until the daily range hits that.


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Old 06/16/2018, 06:30 AM   #18
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Thanks for the info.


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Old 06/16/2018, 04:38 PM   #19
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You're welcome. Good luck!


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Old 06/18/2018, 06:25 AM   #20
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Tested again sunday. Im at 6.7dkh, down .3 or so from friday when i tested at 7.0dkh. The test kit has an accuracy rating of +/- 0.14dkh, so im going to say im still dropping about 0.1-0.15/day.

At the levels i am at, a 20% waterchange will move my dkh somewhere around 1.3dkh. I figure if i dose the tank some to slowly bring my dkh up a little higher, then a waterchange will not cause as big of a swing. And should keep it pretty stable. My salt mixes at 13.3dkh.

Im thinking i want it around 9.5dkh, does this number sound reasonable? What is a good place to keep alk and ca for fastest growth rate?


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Old 06/18/2018, 10:02 AM   #21
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I also use the salfert test kits. I find it is easiest to do the test in front of a window. Much easier to see the color change for me. Though my neighbors must think I might be cooking meth watching me drip and swirl once a week.
HAHA


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Old 06/18/2018, 12:26 PM   #22
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In theory, higher alkalinity levels will encourage more growth, up to the point that the corals are limited by food or light. I think 9.5 dKH is high enough in practice. Some tanks seem to have coral problems if the level gets much above 8 dKH, although that seems to be due to carbon dosing. I'd try 9.5 dKH and see how it goes.

Calcium at 400-450 ppm should be fine. I don't see any reason to go higher.


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Old 06/18/2018, 02:26 PM   #23
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A drop of 3 dKH (from 9.5 dKH to 6.5 dKH) corresponds to about a 22 ppm drop in calcium, which is close to our testing limits. There are some processes that will consume alkalinity but not calcium, though:

http://reefkeeping.com/issues/2004-12/rhf/index.htm
Isnt it close to ~54ppm. 1 dKH alk is ~17ppm CO3- . With 1-1 consumption, wouldn't it be 53 ppm CO3- and 53ppm Ca.



Last edited by Tripod1404; 06/18/2018 at 02:34 PM.
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Old 06/18/2018, 02:34 PM   #24
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In theory, higher alkalinity levels will encourage more growth, up to the point that the corals are limited by food or light. I think 9.5 dKH is high enough in practice. Some tanks seem to have coral problems if the level gets much above 8 dKH, although that seems to be due to carbon dosing. I'd try 9.5 dKH and see how it goes.

Calcium at 400-450 ppm should be fine. I don't see any reason to go higher.
I think the issue is more with low nutrients rather than carbon dosing. I dont dose carbon but my nitrate is at 1ppm with KNO3 dosing and phosphate sometimes do not register anything but zeros at Hanna ULR for weeks.

If my alk goes above ~7.8 dkh for a prolonged period (as little as few days), my SPS lose all PE and brain corals deflate.

At 7.5dKH, my daily alk consumption is at 2.5dKH. A while ago, I tried keeping it at 8dKH to see if I would get more growth. After a week of doing it my daily alk consumption dropped to 1-1.5dKH and acros montis start to get burned, so I stopped and let it drop to 7.5 dKH.

So it makes me believe lower alk can give better growth under conditions where nutrient levels are otherwise limiting.


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Old 06/18/2018, 09:57 PM   #25
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Isnt it close to ~54ppm. 1 dKH alk is ~17ppm CO3- . With 1-1 consumption, wouldn't it be 53 ppm CO3- and 53ppm Ca.
It's 2.8 dKH per 20 ppm calcium. The ppm numbers aren't equal, for various reasons.


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