Swinging Parameter nitemare.. Reef Chem experts I need a fresh eye.

[MammothReefer]

I'm driving myself batty over here. I've been keeping reef tanks for almost a decade now and I've never had this issue with any other system.
This isn't my first run in the park w/a heavy sps tank either.

I can't for the life of my get my alkalinity to stabilize. It's requiring daily/tri-weekly testing, and bi-weekly adjustment. Numbers that produced one result one day produce a different result a few days later. I've managed to keep my tank growing by keeping on top of it...but this isn't how it's supposed to work ha.

Another set of eyes, or any suggestions would be greatly appreciated I really don't want to burn myself out on my tank but I'm going on month and months of what I believe is now a maniac level of husbandry. So if you can please review my logs (below), or if you have any ideas thoughts I can use the help. :headwally:

The Problem:
Alkalinity will not stabilize. I can get the same results for a couple days in a row and the 3rd day it will simply start climbing/dropping by .5-.7dkh a day, or it will start moving then just stabilize then rise then drop. If I shut off my alkalinity dosing some days it will drop a steady .5dkh some days it will not drop it all.

(example 2 days in a row I'll have .08 dkh movement in alk with a set dosage on the 3rd day my alk will then spike by .6dkh, and continue on forward, or in the opposite I'll turn off my alk doser and alk won't move for one day, the next day it will drop by .5dkh, and the 3rd day not at all again, my favorite so far is I had one grouping of tests where I had it adding .2dkh every day for 2-3 days, I then left town for 4 days only to find my dkh had dropped by 1.5 dkh from the prior test, when I expected it to RISE by .8dkh so it had a theoretical swing of 1.8 dkh) !)


What I've done:
I've tested the dosing pumps by having them pour 24 hours of dosing into a measuring cup on multiple occasions and even over multiple days. All tests have come back +/- 1ml (based on eye accuracy)

I've kept logs of all my tests ran as many as I could withing a very tight time frame, I've ran tests for weeks w/out adjustment.

I've ran controlled tests where I "reset" my alk back to a specific DKH on multiple occasions to look for similar results.

I've ran multiple tests at the same time for testing accuracy.
I've ran tests w/multiple test kits and compared differences for accuracy (salifert and hanna kits both are reading very comparable).

I do not adjust alk w/out adjusting calc.

I do not adjust to chase a number, I adjust for stability/Constancy. (I don't care where I'm at between 8-9 as long as it's stable)

Tried different adjustment ranges from .5ml a day to 4ml a day. (most are 1ml a day changes)

Make sure lines aren't clogged daily.

I try to give myself a couple days between adjustments to give things time to "acclimate"

I feed on a regular schedule, a small variety of foods. (Mysis, Pellets, Nori, reef roids, and oyster eggs).

Once a week I feed LPS.


Things to note about the system.
Alk + Calcium are running at equal dosing amounts.
Mag does seem to have a steady draw that I manual top off when I do my full gambit of testing just prior to water changes.

I have not changed the supply of alk or calc during the duration of these tests.

My reef tank is now requiring approx HALF dosage amount I was just several months ago.

The tank/system is about 13 months old.

I'm running a SSB.

I've had very few additions or changes to the tank in the last few months (or over the course of the summer)

The tank volume is 65gallon display, 40 gallon sump, and a 15gallon LPS tank.

I have a some what limited divisibility of corals imop. (The main tank is Acros/Montis/Enchinos/Stylos/Acan Bowerbankis, the LPS is Acan lords/1 Unknown Acan, and frogspawn/hammer). 1 Softie (clove polyps), No Anenomes, no leathers, zoas, shrooms, etc (outside of a few aptasia)

Fish load is medium. 2 tangs, 3 wrasses, 2 clowns, a damsel, a blenny, and a dottyback.

I run GFO/GAC that I change when I notice any increase in phosphates.

Outside of trace elements (which I dose maybe once/twice a month when I find myself looking at the bottle of snake oil wonder why I wasted my money on it) I don't dose anything.

I baste my tank a few times a week, and have started blasting my tank again once a week for a AEFW break out I had in the spring. (which seems to be under control again but I will keep up the blasting/basting)

Other parameters are all within "acceptable" ranges and appear to be stable/predictable.

Lights, heaters, dosers, top off all controlled and on a regular schedule.


(last full gambit test 10/16/11)

10/16/2011
21:15:00
Salinity 1.024 (refracto)
Calcium 430 (salifert)
Alk 9.184 (hanna)
Mag 1400 (salifert)
PH 8.2 (controller)
Phos 0.03 (hanna)
Nitrate .5-.2 (salifert)

SPS is not dying and is doing fine but I believe it's only due to my diligence of making sure I don't move out of an acceptable range in the event I notice an increase/decrease of alkanlity either below 8, or trending above 9.5 I will reduce/increase it back to about 8.5 and "start over"

For the most part water changes are done regularly 10-15gallons weekly with the exception of a few week period when I was trying to make as little modifications to the tank as possible for testing sake.

Here is a link to my log files I keep notes on the right hand side, the past 2 months have been when I've been testing alk before that it was some what steady, and there were decent sized periods of time where I didn't test.

https://docs.google.com/spreadsheet/ccc?key=0AiJkwwBTLCi7dG12ZFhsTXBGTUFZellSWTZ3QkhiLVE&hl=en_US

Thanks again for any help or insight.

 

[tmz]

The variability within 1 dkh may prove to be more precision than you can manage with hobby grade testing and dosing equipment. Variability in consumption by calcifying organisms , CO2 levels, and other variables like gfo may effect some of it and testing equipment is not as precise as we'd like. I settle for a preset dose of saturated limewater and an occasional tweak with baking soda as needed. Alk runs in a range of 8.6 to 10 dkh with 9.6 the mode.

 

[MammothReefer]

The variability within 1 dkh may prove to be more precision than you can manage with hobby grade testing and dosing equipment. Variability in consumption by calcifying organisms , CO2 levels, and other variables like gfo may effect some of it and testing equipment is not as precise as we'd like. I settle for a preset dose of saturated limewater and an occasional tweak with baking soda as needed. Alk runs in a range of 8.6 to 10 dkh with 9.6 the mode.

Thanks Tmz for the quick response. I don't know if I can afford such a large swings for my SPS (for some reason things are just extra picky for me lol.. I don't have a blue thumb! ) . I'm running a hanna tester which matches up to my salifert pretty accurately so if I'm getting 2 different tests giving me similar results can the results vary that much? I'd like to get my tank to settle back in the lower DKH range so I can return to biopellets (been offline for 6-8 months now), but I can't do that if my ALK is getting above 9dkh. I tried limewater for quite some adding it w/my top off it worked with my other systems, and it my smaller tanks but the top off requirements of this tank are to unstable so I was getting rather large swings dependent on the humidity/weather.

PH for my tank is surprisingly stable. Typically swings between 8-8.3 everyday. Unfortunately I do have C02 build up in my house during the winter when I can't open any windows or doors so I'm expecting my PH levels to take a dip over the upcoming months.

Edit: In regards to the GFO. I know it can effect ALK. I haven't changed it since I've tried to get things to stabilize again.

 

[djkms]

I was in the same boat as you only I use a CA reactor.

My solution:
kalk reactor hooked up to ATO. My alk does not swing more that 3ppm between weekly tests now. My ATO tops off with a Tunze Osmolator hooked up to my neptune apex. It only tops off 1 minute every 2 hours and does not turn on if PH is higher than 8.3. I turned down my CA reactor just a tad so the kalk maintained the CA and alk. Only drawback is my magnesium starts to fall after a while so I just add tech-m once every couple of weeks.

Edit: just read you used kalk, I would say use it in conjunction with your dosing..IME kalk only maintains not raises...

 

[MammothReefer]

I was in the same boat as you only I use a CA reactor.

My solution:
kalk reactor hooked up to ATO. My alk does not swing more that 3ppm between weekly tests now. My ATO tops off with a Tunze Osmolator hooked up to my neptune apex. It only tops off 1 minute every 2 hours and does not turn on if PH is higher than 8.3. I turned down my CA reactor just a tad so the kalk maintained the CA and alk. Only drawback is my magnesium starts to fall after a while so I just add tech-m once every couple of weeks.

Edit: just read you used kalk, I would say use it in conjunction with your dosing..IME kalk only maintains not raises...

I very much liked using kalk, but my tank can go from evaporating a half gallon a day to 2-3 gallons a day during a big snow storm. I don't know if it's the altitude or what do you have those issues in CO?

 

[tmz]

Ime, small swings in alk don't hurt sps as long as they don't dip below 7.5dkh. The more constancy the better though.Why do you think you can't go above 9dkh with organic carbon dosing? It's not a real issue ,ime.
Kalk adds calcium and the oxide joins CO2 to form carbonate. It adds them in the same proportions as a calcium reactor or 2part dosing. So depending on consumption it may raise them not just maintain them. In any case at fulllsaturation it's enough for my low nutrient system which is laden with growing sps, mixed corals and well fed fish. I used a calcium reactor alongside kalk dosing for a couple of years. It now sits on the shelf and kalk with a rare tweak of baking soda takes care of calcium and alk with greater constancy and more purity.
I dose a preset amount per day, approximating top off from a still reservoir using a perstatltic pump.. The amount pr day can be adjusted seasonally or supplemented with ro water to the sump when evaporation variances dictate.

 

[MammothReefer]

Ime, small swings in alk don't hurt sps as long as they don't dip below 7.5dkh. The more constancy the better though.Why do you think you can't go above 9dkh with organic carbon dosing? It's not a real issue ,ime.
Kalk adds calcium and the oxide joins CO2 to form carbonate. It adds them in the same proportions as a calcium reactor or 2part dosing. So depending on consumption it may raise them not just maintain them. In any case at fulllsaturation it's enough for my low nutrient system which is laden with growing sps, mixed corals and well fed fish. I used a calcium reactor alongside kalk dosing for a couple of years. It now sits on the shelf and kalk with a rare tweak of baking soda takes care of calcium and alk with greater constancy and more purity.
I dose a preset amount per day, approximating top off from a still reservoir using a perstatltic pump.. The amount pr day can be adjusted seasonally or supplemented with ro water to the sump when evaporation variances dictate.

Thanks again for the response.

You don't want to be carbon dosing with high alk, the closer to NSW the better. You end up with a lot STN/burn tip issues when you combine carbon dosing and high alk.

Why I don't like to go above 9, is because I don't trust my test kits ha. So I figure If I'm in a range of 8-9. Then I'm safe +/- 1 won't really matter. However if I'm running 10dkh and my test kit is wonky then I could really be @ 11 which for carbon dosing would be disastrous.

Either way though the level isn't the issue I'm just looking for stability. The problem with kalk is the day by day change in demand due to the weather. I am pretty sure I could get by with Kalk alone at this point or only a small dose if I could keep it stable. I'm only dosing 36ml a day of 2 part, but the swings are just to great. I'm really trying to get my tank to move no more then 1DHK over the course of a week which is still a good sized swing imop. That way every weekend when I do my water change I can "reset it".

I'm just trying to figure out why I can't get things to stabilize. A year old tank with very little changes, should be humming along at this point.

 

[tmz]

You don't want to be carbon dosing with high alk, the closer to NSW the better. You end up with a lot STN/burn tip issues when you combine carbon dosing and high alk.

Don't think that's true even though it's a common statement by some folks with " "ulns" systems,a rather meaningless term. If you can run it a 6.5dkh carbonate alkalinity which is seawater and get good growth that's fine but the odds for dropping below a critical threshold are greater,imo.
Going higher offers more calcification and growth. If the coral symbionts are starved for nitrogen and /or phosphorous due to overuse of organic carbon perhaps encouraging growth is too much for them or perhaps some bacterial activity becomes pathogenic,perhaps glucose or fermentation activity is an issue or organic carbon buildup. In other words perhaps alk level is not the culprit for burnt tips. No one knows with certainty.and there isn't any data or plausible hypothesis of which I am aware to support the alk /burn notion. I do know with PO4 under .04ppm and nitrate around 0.2 ppm with via vodka/vinegar dosing you can run 10 dkh (per salifert and api ) whitout any trouble. I've been doing it for almost 3 years.

I think 8 to 9 are good targets given the uncertainty of hobby grade testing as well. Personally, I choose to go a bit higher.

The stability in alk will be easier to get if you also stabilize a few significant external variables: including CO2 levels as evident in (ph), organic carbon dosing levels, PO4 stability , time of day you test,growth by calcareous organisms , a consistent dosing regimen for alk and calcium, good magnesium levels, consistent use of a salt mix with the same alk and calcium,consistent specific gravity and so on.
Alkalinity is not a thing ;it's a measure of a number of things that neutralize acids including carbonate CO3, bicarbonate HCO3 ,PO4, borate and a few others. The corals use only the carbonate/bicarbonate alkalinity which is about 96% of the total in seawater( so for those of us using alk to support stony corals and other calcareous organisms, the typical test for total alkalinity seres as a surrogate measure for carbonate and bicarbonate) The 96% proportion may be more or less depending on the composition of the salt mix and buffers used.
Alk varies with ph . Inorganic carbon species: CO3(carbonate) HCO3 bicarbonate and CO2 and/or H2CO3, carbonic acid;shift back and forth depending on the amount of H + in the water which in turn relates to CO2 which when hydrolized frees up H from the water itself. CO3 has 2 alk units(open binding sites ) as opposed to only one in HCO3 and none in H2CO3. So as it shifts the alk measure shifts too. In this sense too it's a moving target.

I'd start toward the low end of the acceptable range (7 to11 dkh) say 8.0 or so,dose your choice of supplement( mine is kalk) at a consitentl level for a week . Recalculate need go another week , testing along the way . while doing so pay close attention to constancy for the other variables.

 

[MammothReefer]

Thanks again Tom for your prompt response and your time to help me with this issue. I'd rather not get into a big debate about Carbon Dosing, and Alk levels. I'm not carbon dosing at this time and haven't since some time mid last winter. I feel it may become a bit of a distraction from the main stability issue I'm having. Regardless of my "target' alk. I just want it to be stable. I re-tested again today, and hit the just a slightly higher number (still with no change in settings) then yesterday but with that I also tested about an hour later then normal so it could have simply been an extra dosage.

The 18th my alk was at 8.568 (10:20pm)
the 19th it was at 8.456 (10:30pm)
The 20th it jumped up to 9.128 (10:17pm)
and on the 21st it tested @ 9.128 (7pm), and 9.24 @ 11:15

In reading what you are saying. I hope this answers/address some of your points/questions.


- My P04 is showing signs of stability it's been at .03 for the month of oct.

- My PH. Seems to run the same pattern and seems to move between 8-8.3 (lately 8.2 max) Which I believe is acceptable.

- I'm not doing any organic carbon dosing at this time.

- The time of test is almost always within 10 mins of each other (minus today which was an a reactive set of test when I found an acropora RTN'ing That has been doing very well for me for the past 6-8 months or so, always held it's colour great growth, great pe not sure why it started go from the bottom up today as my tests are showing anything out of line. It's been fragged, and glue'd and hopefully will recover.)

- My Dosing regiment is consistent it's controlled by my ACJR, and I've tested to make sure the correct amount of is actually being pumped (by pumping into a measuring cup for multiple 24 hour periods)

- My magnesium has been at great levels with small fluctuations from 1380-1440 since mid/early sept (before that I had a mag issue for a couple months)

- My current salt mix does run a little higher then my desired alk but matches my current levels. I'll be switching to a brand with lower alk when this batch runs out. All batches are made the same (3 cups per 5 gallons very consistent mixed for 24+ hours)

So with that your saying my actionable item is to switch from a 48 hour test / adjust window to a week long test adjust window? Since I already have 4 days under my belt of non-adjustment I may as well let it go for 2 more (unless it really spikes up and hits the 10s, since I'm going to be doing a water change on Sunday eve).

The only other thing I can think of is to run my skimmer air line threw my wall into the garage (already have a hole that I can up cap from my old 500g system). So I can pull in "fresh" air vs closed up house air.

I wouldn't mind adding kalk into the mix, but I hate to add something new to the equation I've been able to balance a tank w/2 part in the past. Why I can't get it now is beyond me.

Thoughts?

Thanks once again for your time.

 

[tmz]

You are welcome.


So with that your saying my actionable item is to switch from a 48 hour test / adjust window to a week long test adjust window? Since I already have 4 days under my belt of non-adjustment I may as well let it go for 2 more (unless it really spikes up and hits the 10s, since I'm going to be doing a water change on Sunday eve).

The only other thing I can think of is to run my skimmer air line threw my wall into the garage (already have a hole that I can up cap from my old 500g system). So I can pull in "fresh" air vs closed up house air.

Frequent testing is not a bad thing. I test alk weekly,more frequent is fine ; but obsess on PO4 and test it daily. Holding off on tinkering with a dosing adjustments for a few days absent a significant change in levels( .5 or more) is what I'm suggesting. I use salifert and api tests for alk. Don't know how accurate or consistent the hannah checker is. Testing noise could be contributing to variations.

8.2 ph is fine and the swing which is small wouldn't be an issue even if it were larger. Much larger swings occur on natural reefs.

If you do choose to run an airline to the skimmer at some point make sure its large enough not to restrict airflow thru the skimmer. The longer it is the larger the inside diameter should be.

If you suspect room air is high in CO2, you can test it's ph by aerating a water sample from the aquarium for a few minutes inside the room and measuring ph. . Then take the same sample and aerate in outside for a few minutes and test the ph .If the outside test shows lower ph , your inside air has higher CO2 than the atmospheric level outside.

 

[MammothReefer]

Hmm odd, I'm seem to be holding steady now, tonight again I got 9.24

The 18th my alk was at 8.568 (10:20pm)
the 19th it was at 8.456 (10:30pm)
The 20th it jumped up to 9.128 (10:17pm)
21st it tested @ 9.128 (7pm), and 9.24 @ 11:15
22nd, 9.24 @ 10:30pm

Was a post on RC all I needed? or could it be that I'm keeping it a higher alk is it possible that my alk for whatever reason unknown to me won't stabilize at a lower level? Could be because my calc/alk/mag isn't at the right ratio to allow for a DKH of 8-8.5?

3 Days in a row with relative the same DKH is a record for me as of late.. ha. ..what's odd is I've changed nothing just be watching at this point. I guess I'll test and do my water change tomorrow and see how it goes from there.

 

[reefkeeps]

I totally understand your challenge, thank you for posting it, mine does the same thing, and I'm dosing 2 park and Kalk. Also using the Hana checker

12-Oct am 8.4
13-Oct pm 8.4
14-Oct am 8.288
15-Oct am 8.232
16-Oct am 7.672
17-Oct am 8.4
17-Oct pm 7.952
18-Oct am 8.344
18-Oct pm 7.896
19-Oct pm 7.952
20-Oct am 8.848
20-Oct pm 8.176
21-Oct am 8.456
21-Oct pm 7.784
22-Oct am 8.288
22-Oct pm 7.56 (no idea why it dropped that low)
23-Oct am 8.288

 

[bertoni]

I suspect that the 7.56 reading is an error of some sort, unless you had a lot of people in the room that day.

 

[MammothReefer]

Why an error he has 6 readings in the 7s

 

[reefkeeps]

16-Oct am 7.672
17-Oct am 8.4
17-Oct pm 7.952
18-Oct am 8.344
18-Oct pm 7.896
19-Oct pm 7.952
20-Oct am 8.848
20-Oct pm 8.176
21-Oct am 8.456
21-Oct pm 7.784
22-Oct am 8.288
22-Oct pm 7.56
23-Oct am 8.288
23-Oct pm 7.728

It's low tonight as well

It's crazy, I add 150ml of 2 part a day and 3000ml of Kalk...

 

[djkms]

16-Oct am 7.672
17-Oct am 8.4
17-Oct pm 7.952
18-Oct am 8.344
18-Oct pm 7.896
19-Oct pm 7.952
20-Oct am 8.848
20-Oct pm 8.176
21-Oct am 8.456
21-Oct pm 7.784
22-Oct am 8.288
22-Oct pm 7.56
23-Oct am 8.288
23-Oct pm 7.728

It's low tonight as well

It's crazy, I add 150ml of 2 part a day and 3000ml of Kalk...

Look at your history, it actually makes sense. Calcification is probably most "active" during the day when lights are on and less so when lights are off. I know when I do a 3 day lights out with my tank my CA and ALK shoot up. You numbers are higher in the AM then PM.

MR - not sure I notice issues being a mile high...well.. maybe I do. I struggled keeping a high PH until I started using kalk. Most say its because my CA reactor but I disagree. My PH (before alk) was between 7.7-7.9 and now with kalk its 8.15-8.35. The reason i dont think its because of my CA reactor is because I have my effluent at the highest point of my sump (long air time) with a slow drip (1 bubbles per second) and it falls right next to my skimmer pump. Doubt much CO2 is getting back in my system but I could be wrong. Not sure PH has anything to do with altitude though.

As far as evaporation, no clue how much, a guess would be about 1 1/2-2 gpd (140 gallons total system volume). Not sure it changes much day to day, my ATO is with my kalk-tunze osmolator and its pretty much out of site out of mind.

 

[tmz]

The calcium reactor is dumping effluent with a ph of 7 or less. Not much will change in a brief freefall,imo. The kalk at full saturation is 12.5.
I don't think when calcification occurs night vs day is very clearly understood. There is typically more CO2 at night which could effect ph and alk.

 

[MammothReefer]

That didn't work out well. Tank did not like running @ 9.4 started to get some burnt tips, and one piece that I've had for along time started to RTN I did a water change and shut the alk/calc off for 48 hours which dropped it back down a point. Tonight I'm turning it back on at a very slightly reduced amount hoping to get it to hold steady @ 8.5. I wouldn't mind even letting it drop down to 8.0 but I think .5dkh a day drop over the course of 3 days would be to quick since some things are already getting touchy.

What I do find odd though is even though I had a reduction in ALK, I saw no reduction in calcium, it makes me wonder if I should shut off calcium and leave alk running for a few days until I start to see some movement.. maybe even try running / keeping calcium @ 380 vs the current 430

This was my result of 6 days w/out touching anything

The 18th my alk was at 8.568 (10:20pm)
the 19th it was at 8.456 (10:30pm)
The 20th it jumped up to 9.128 (10:17pm)
21st it tested @ 9.128 (7pm), and 9.24 @ 11:15
22nd, 9.24 @ 10:30pm
23rd, 9.408 @ 10:15pm

(again link to my spread sheet)
https://docs.google.com/spreadsheet/ccc?key=0AiJkwwBTLCi7dG12ZFhsTXBGTUFZellSWTZ3QkhiLVE&hl=en_US

 

[bertoni]

Calcium drops 20 ppm for every 2.8 dKH drop in alkalinity, so changes tend to be hard to detect on that scale. I'm sorry to hear about the RTN.

 

[MammothReefer]

Calcium drops 20 ppm for every 2.8 dKH drop in alkalinity, so changes tend to be hard to detect on that scale. I'm sorry to hear about the RTN.

Thanks I fragged and glue'd and I have a few "blobs" where it had grown onto the rocks that are doing ok.. it might not be a nice colony as it was before but at least I didn't loose the whole piece.

I guess since I only dropped about 1dkh, I should have seen in theory about a "7ppm" drop. Ya I can easily be off by a drop w/the salifert kit.

I still wonder though if I should shut off my calc to let it be more inline with where I want my AlK to be..hoping it will balance out easier.