Falling Alk levels on Frag System

[zpete3323]

Hello all,

I am bamboozled over my dropping alk levels in my 500g frag system. Over the past week I have continually dropped .1DkH/day no matter how much I increase my kalk dosing. I am now sitting at 7.78DkH vs my traditional 8.7 I tend to run

I usually dose around 2800-3000mL of kalk solution via Apex Dos throughout the day but have since increased it to 7500mL with NO change in the falling alk. I even set the kalk stir to mix every 30min vs 2hrs to promote a higher concentration of kalk effluent
(I use an Icecap KM-200)

I even double checked with actual test kits to check my trident was not drifting but it was dead on...

Weekly swing was:
Alk: 0.9DkH
Calc: 20ppm
Mag: 40ppm

Any suggestions would be amazing!

 

[Timfish]

Sounds like stuff is growing. Don't forget other organisms besides corals use it. Also, the ratios used of alkalinity, calcium and magnesium may be vary so keep monitoring all three.

 

[92Miata]

I see significantly lower magnesium recently on that chart - did you dose a bunch?

Have you tested the pH of your kalk stirrer/reactor/effluent? How long has it been since you dumped it, cleaned it out, and replaced all the kalk? I really doubt your uptake increased by that much in a week - so the culprits are either that it's precipitating out, or you're not getting potent effluent.

I suppose another potential culprit is that your dosing pump is slipping/backsiphoning/etc. How old is tubing/when is the last time you calibrated it? Maybe try measuring one of your scheduled doses.

 

[nick7948]

Hello all,

I am bamboozled over my dropping alk levels in my 500g frag system. Over the past week I have continually dropped .1DkH/day no matter how much I increase my kalk dosing. I am now sitting at 7.78DkH vs my traditional 8.7 I tend to run

I usually dose around 2800-3000mL of kalk solution via Apex Dos throughout the day but have since increased it to 7500mL with NO change in the falling alk. I even set the kalk stir to mix every 30min vs 2hrs to promote a higher concentration of kalk effluent
(I use an Icecap KM-200)

I even double checked with actual test kits to check my trident was not drifting but it was dead on...

Weekly swing was:
Alk: 0.9DkH
Calc: 20ppm
Mag: 40ppm

Any suggestions would be amazing!

Have you added anything recently that could be absorbing the Alk? This has happened to me twice over the years. Once was when I added a few dry rock. Usually when I add dry rock this doesn't happen, so it must have been the type of rock. I do know that some rock (forget where from) needs a long time to cure, which may have been related. The second time was when I changed from a bare-bottom to a sand/rock bed. I added the sand/rock (crushed coral) slowly but it still caused a a lot of Alk leeching. In both situations I had to triple my alk dosage to even get it to slow down - without a Trident my SPS would have certainly died. One other time that this happened which wasn't related to leeching was simply my tubing being clogged. I didn't notice it since the Apex was still reporting the dosing but when I manually pushed the button on the DoS nothing was coming out. Hope you get this fixed soon.

 

[TokenReefer]

Wouldn't increased growth (from the kalk) also lead to increased alk consumption? Hand in hand I thought

 

[loui]

Are you verifying your test results or are you hoping your trident is correct?

 

[zpete3323]

I see significantly lower magnesium recently on that chart - did you dose a bunch?

Have you tested the pH of your kalk stirrer/reactor/effluent? How long has it been since you dumped it, cleaned it out, and replaced all the kalk? I really doubt your uptake increased by that much in a week - so the culprits are either that it's precipitating out, or you're not getting potent effluent.

I suppose another potential culprit is that your dosing pump is slipping/backsiphoning/etc. How old is tubing/when is the last time you calibrated it? Maybe try measuring one of your scheduled doses.

The large bump in magnesium was due to a waterchange I preformed a few days ago. It jumped from 1240 to 1280. Not a terrible jump but with that small of a change window across a week it looks like a large bump.

The kalk reactor was dumped, cleaned, and refilled around 2 or 3 weeks ago. I will check the ph of the effluent as soon as I get home tonight never thought of that!

I will also try recalibration the dos unit like you said I bet that is the culprit. The unit was installed Jan of 22 so still newish but DEFINITELY could use some attention after 10mo of operations without a thought on my part.

Thank you!!

 

[zpete3323]

Have you added anything recently that could be absorbing the Alk? This has happened to me twice over the years. Once was when I added a few dry rock. Usually when I add dry rock this doesn't happen, so it must have been the type of rock. I do know that some rock (forget where from) needs a long time to cure, which may have been related. The second time was when I changed from a bare-bottom to a sand/rock bed. I added the sand/rock (crushed coral) slowly but it still caused a a lot of Alk leeching. In both situations I had to triple my alk dosage to even get it to slow down - without a Trident my SPS would have certainly died. One other time that this happened which wasn't related to leeching was simply my tubing being clogged. I didn't notice it since the Apex was still reporting the dosing but when I manually pushed the button on the DoS nothing was coming out. Hope you get this fixed soon.

I added a batch of corals from Battlecorals and from aquashella within the last month. Nothing has changed since then.

I run sand in 1 of the 3 tanks but the rest are bare bottom and egg crate racks. Should probably add some live rock for a buffer but don't have any currently... future additions!

I will check on the dos unit. I see it piddling out when it runs but I bet it need recalibrated now that it is about 10mo old.

Thank you!

 

[zpete3323]

Are you verifying your test results or are you hoping your trident is correct?

Yes,

All test results are double checked with manual AP tests/properly calibrated digital tests. All 3 ran nearly identical in their results