Where are my Chemicals Going?

[Ted_C]

Hi All.

I've been dosing BRS / Randy's 2 Part Recipe A for quite a while now. Before that, I was adding Brightwell Code A+B. I also tried using some Sealab 28 a few months ago too along with dosing.

I have a 120 gallon display filled with around 30 different species of SPS (all started from frags ~1-2 inches) thats been running around 6 1/2 months now. I have about 50 gallons running through a 90 gallon sump (so total system volume is 170 gallons).

In these past few months, I have had a tough time getting the alkalinity balanced. It was a weird situation too - no matter how much Alk I dosed, my Calcium was staying pretty steady at 480 PPM - so I was dosing very little Calcium

Once I got the alkalinity stabilized - the calcium started dropping. So I increased the calcium dosing.

I'm currently dosing 225 ml Ca, 225 ml of Alk and 50 ml of Mg per day. Below is my testing starting in March and my notes. Does that sound unusual? I just feel that (after searching to see what others are dosing) I'm putting alot into the tank and not seeing a return in the growth of the corals. So where in the heck am I getting this consumption?

Date kH meq Ca (PPM) Mg (PPM) Notes
3/10/2013 7.3 2.6 410 1200 20 Gal Water Change, 30 ml / day dose brightwell
3/11/2013 7.3 2.6 410 1200
3/12/2013 7.6 2.7 420 1240 50 ml brightwell dose
3/13/2013 8.1 2.9 430 1240 50 ml brightwell dose
3/14/2013 7 2.5 400 1240 Did not dose
3/15/2013 7.8 2.8 410 1200 Only dose 35 ml to make up for yesterday
3/16/2013 7.8 2.8 400 1200 Dosed 50 ml to make up demand
3/17/2013 7.8 2.8 400 1200 Does another 50 ml, Dosed 60 ml 6 PM
3/19/2013 8.7 3.1 400 1280 35 ml @ night, 35 ml morning, 20 gallon waterchange
3/20/2013 9.7 3.3 450 1200
3/21/2013 8.1 2.9 480 1240
3/22/2013 7.8 2.8 460 1160 Sealab 28: 4 cubes spent, dosed 35 ml Brightwell code B only @7:41 PM, scraped back wall of calcified stuff
3/24/2013 9.2 3.3 480 1200 3/23 - wshed out skimmer with 1/2 cup vinegar. Added MP10 to back wall
3/25/2013 8.7 3.1 480 1200
3/26/2013 8.4 3 480 1200 Dosed 40 ml CodeB @6:32 PM 3/26
3/27/2013 8.7 3.1 470 1200
3/31/2013 7.8 2.8 460 1160
4/1/2013 8.7 3.1 460 Dosed 35 ml code b @ 7 AM
4/2/2013 8.1 2.9 460 1200
4/3/2013 8.1 2.9 460 1200
4/4/2013 8.7 3.1 440 1200
4/7/2013 9.8 3.5 460 1200
4/17/2013 9.2 3.3 470 1160
4/18/2013 8.7 3.1 470 1160
4/21/2013 9 3.2 470 1240 New Red Sea test kit. Dosers running since 4/15
5/19/2013 5.6 2 430 1240
5/23/2013 7.6 2.7 490 1360
5/24/2013 8.4 3 490 1280
5/25/2013 8.7 3.1 490 1400
5/27/2013 9.2 3.3 480 1360
5/28/2013 9.5 3.4 450 1280
5/29/2013 9.5 3.4 470 1300 130 ml Ca, 150 ml Alk, 100 ml
5/30/2013 9.5 3.4 460 1320 125ml Ca, 150 ml Alk, 50 ml Mg
5/31/2013 9.5 3.4 450 1320 125ml Ca, 150 ml Alk, 50 ml Mg
6/3/2013 9.8 3.5 450 1320 130ml Ca, 160 ml Alk, 50 ml Mg
6/4/2013 10.4 3.7 440 1400 130ml Ca, 160 ml Alk, 50 ml Mg
6/5/2013 10.1 3.6 440 1360 140 ml CA, 150 ml ALK, 40 ml MG
6/9/2013 9.8 3.5 430 1240 140 ml CA, 185 ml ALK, 40 ml MG, 15 gal water change - Red Sea on 6/8
6/10/2013 9.8 3.5 420 1280 150 ml CA, 195 ml ALK, 50 ml MG
6/11/2013 10.1 3.6 420 1360 160 ml CA, 210 ml ALK, 50 ml MG
6/13/2013 10.1 3.6 410 1360 175 ml CA, 210 ml ALK, 50 ml MG
6/15/2013 9.2 3.3 420 1360 200 ml CA, 210 ml ALK, 50 ml MG
225 ml CA, 225 ml ALK, 50 ml MG

 

[fazilosman]

What kind of test kits are you using? are you double checking the results with another kit?

I was having about the same issue when using the Hanna CA test. My CA was all over the place and I was constantly chasing a fictitious number. I then used RedSea for CA and it has been rock solid at 480.

So, a few thoughts...

1) Are you seeing any precipitation at the doing area or on the pumps? This could explain the swings.

2) How is the coraline algae growing? Fast - could be using up Alk and CA.

3) Try to keep both doses the same and see where the numbers settle. I would simply forget about CA for a while and tweak the dose to replace Alk only until that is stable. Once your Alk is stable then CA can be modified with turbo calcium or something like that.

4) What are you using for WC's? What is the frequency of the WC? Have you tested you make up water? If your make up water is far off the tank levels, then every time you perform a WC, you will either increase or decrease these parameters.

My advice is stop chasing the perfect number (I know from experience)! I am a little OCD myself and had to just back away and let things settle down by them self. Again, using only one param, ALK get that stable and then tweak from there!

Good luck.

 

[Ted_C]

Thanks Faz -
Using Red Sea Pro test kits Since March - before that was Saifert which I think initially caused my depleted Alk (since it reads high).
1 - No Precipitation - no nodules growing anywhere that I can see. I did have this problem before when I was dosing Brightwell and had a sand bed . I scraped everything off and started BRS - I did the scraping around the 3/21 time frame.
2 - Coraline is growing well - on the Pukani rock, in the sump.I cant tell you if its fast growth or not. I have no comparison to slow growth coralline.
3 - Once my Alk got back to reasonable levels - thats when I noticed the Ca starting to drop. Around the 5/25 time frame - you can see from my log that the Alk started getting into the 9 range. As soon as I hit that point - the Ca started dropping (so I started increasing that dose).
4 - Water changes - I've changed out 100% of the water during my sand siphon project I had going on. Between 4/21 and 5/19 I was using 17 gallon water changes to siphon out my sand bed (with reef crystals IO). My last water change was last week with 15 gallons of Red Sea Coral Pro salt. My next water change will be next weekend with another 15 gallons. Otherwise - I've been pretty regular with water changes - around once every two weeks and around 10% of system volume.

Chasing is exactly what I'm doing - trying to get into some coral growth numbers recommended by Red Sea. They target 12 dkh, 465 PPM ca and 1390 PPM Mg..

I think what I may need to do is shut off those dosers for a month or so and perform a few bigger water changes and let it stabilize so I can see my true consumption.

 

[fazilosman]

Thanks Faz -
Using Red Sea Pro test kits Since March - before that was Saifert which I think initially caused my depleted Alk (since it reads high).

I use RedSea Alk test to backup my Hana Alk test. They are pretty much the same reading for me. So I do trust the Red Sea kit.

Thanks Faz -
1 - No Precipitation - no nodules growing anywhere that I can see. I did have this problem before when I was dosing Brightwell and had a sand bed . I scraped everything off and started BRS - I did the scraping around the 3/21 time frame.

Ok, so it's not precip'ing which is good! Are you using BRS two part now? That's my regimin also - FWIW

Thanks Faz -
2 - Coraline is growing well - on the Pukani rock, in the sump.I cant tell you if its fast growth or not. I have no comparison to slow growth coralline.

Same setup for me! My 180g is now 10 months old and Pukani is pretty much encrusted with coraline algae. Did have alot of growth on my overflow but keep all the glass clean. Seems like my coraline has slowed recently - maybe just no more place to grow.

Thanks Faz -
3 - Once my Alk got back to reasonable levels - thats when I noticed the Ca starting to drop. Around the 5/25 time frame - you can see from my log that the Alk started getting into the 9 range. As soon as I hit that point - the Ca started dropping (so I started increasing that dose).

With our tanks being so similar in age, capacity and stocking - I personally shoot for 9 - 9.5 dkh and 440 - 480 ca. I have watched and read about the red sea program but am worried about burnt tips due to my fairly low nutrients. I just placed a new milli and tort frags 4x weeks ago and can see the growth via encrustring now. In short, I would suggest these levels instead of the high ones recommended by Red Sea. I also ensure to keep some phosphate (0.04) and nitrate (2) in my system by feeding, AA's and monitoring.

Thanks Faz -
4 - Water changes - I've changed out 100% of the water during my sand siphon project I had going on. Between 4/21 and 5/19 I was using 17 gallon water changes to siphon out my sand bed (with reef crystals IO). My last water change was last week with 15 gallons of Red Sea Coral Pro salt. My next water change will be next weekend with another 15 gallons. Otherwise - I've been pretty regular with water changes - around once every two weeks and around 10% of system volume.

Coral Pro salt has elevated levels of alkalinity and calcium. I would test that makeup water just to be sure. The WC schedule looks good to me and at least any imbalances should be sorted out this way.

Chasing is exactly what I'm doing - trying to get into some coral growth numbers recommended by Red Sea. They target 12 dkh, 465 PPM ca and 1390 PPM Mg..

I think what I may need to do is shut off those dosers for a month or so and perform a few bigger water changes and let it stabilize so I can see my true consumption.

So, I was thinking about this some more this morning and have the following suggestions. I think your dose is WAY HIGH @ 225ml for what you have stocked and growing right now. I would recommend backing the dose down by 1/4 every two/three days. IMHO - you should be in the 100-120ml range BUT that is a guess on my part! I also think you are testing too frequently. Let the tank water settle and get into equilibrium first. I would only test 2x per week and at the same time for every test. Also, resist making big changes on your doser! I try to change by only 5ml/day if any tweaking is needed.

I personally only dose 90ml in my 10 month 180g. That said, I also use Kalkwasser via my ATO and 15% water change every 2 weeks using regular Red Sea salt.

Lastly, I would not shut off the doser right now. I would back down the dose and try to predict what would happen with every change. So, from your 225ml back down to 200ml which is about 10% reduction. Leave it for a few days (3x would be good) and then test the water. I would expect to see a reduction in Alk in a 10% or so range. Record those results and then back down to 175ml, trying to predict with more certainty those results. This way you can determine what is actually happening in the tank.

Forget about the CA at this stage, simply try to get Alk stable as mentioned before. Also, make sure that you are mixing up the chemicals correctly/accurately when making new batches.

I will send you a PM with my log and charts for comparison.

EDIT: also see Randy's article here for scientific explanations: http://reefkeeping.com/issues/2006-06/rhf/index.php also http://www.advancedaquarist.com/2002/11/chemistry

 

[bertoni]

That consumption rate is on the high end, but believable. Coralline algae can consume a lot, for example. I might check for signs of precipitation inside pumps, but I doubt I'd worry much otherwise.

 

[Ted_C]

Thanks Jon and Faz.

I think I'm taking Faz's advice - slowly dropping doing down to 100 ml for both Ca and Alk over the next two weeks and see what happens.

See - something funny happened during all of this dosing that I cant explain. Alkalinity dropped down real low (5 dkH). So something consumed the Alk but wasn't using the calcium. That stayed pretty much rock steady at 450 PPM event hrough the low points.

Once I got alkalinity under control - thats when the calcium started dropping. As I would add more calcium, the alk would start dropping again.

I think I'm finally balanced out and the extra 125 ml (over the 100 ml I think I need) is going somewhere other than coral growth - maybe its getting skimmed out by some miracle maybe its still feeding bacteria. maybe its feeding corraline.

 

[fazilosman]

Thanks Jon and Faz.

I think I'm taking Faz's advice - slowly dropping doing down to 100 ml for both Ca and Alk over the next two weeks and see what happens.

See - something funny happened during all of this dosing that I cant explain. Alkalinity dropped down real low (5 dkH). So something consumed the Alk but wasn't using the calcium. That stayed pretty much rock steady at 450 PPM event hrough the low points.

Once I got alkalinity under control - thats when the calcium started dropping. As I would add more calcium, the alk would start dropping again.

I think I'm finally balanced out and the extra 125 ml (over the 100 ml I think I need) is going somewhere other than coral growth - maybe its getting skimmed out by some miracle maybe its still feeding bacteria. maybe its feeding corraline.

Just take it slowly and try to understand/predict the behavior. Bertoni is correct that your current dose may be correct, and I highly trust his recommendations. Also, please be sure to be consistent on the testing protocol as results can vary depending on how the tests are executed. I say this given the erratic behavior you describe and wonder if you have a large margin of error.

 

[Ted_C]

I've noticed that about the precision/accuracy of the red sea test kits.
+/- 0.2 ml on the titration is +/- .4 dkh (0.1 meq/l) , +/- 20 PPM Ca and +/- 40 PPM Mg I think. That's only the titration side too - consider all of the error that can be added/multiplied through the entire process from aquarium water through the end and your probably talking about +/- 1.0 dkh, +/- 50 PPM Ca and +/- 100 PPM Mg.

I was in college to be a secondary education chemistry teacher (20 years ago) so I'm pretty good at analytical technique and labwork.