Calcium Reactor Issue - Calcium too high

Afm32607

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Question:
How do I lower output of my calcium reactor further while corals catch up in size?

I am in the process of shifting an old 90 gallon reef into a newish, 340 gallon reef. So far, I have transferred most of the coral by numbers, but they are mostly on the small side. The new tank has a calcium reactor instead of a two-part doser, the time needed to maintain the doser was getting to be too much (200 ml per day on the 90 gallon). I have finally got my reactor stable but it seems to be putting too much calcium in as my numbers are getting out of sync. (i.e. Ca is going up and Alk is going down, so I assume the coral are not using enough and the imbalance is coming from the excess additives). Its going slowly but I would like to have that stop, so I don't have to add two part in. Measurements are below but I have a calcium reading of 500, I don't mind the number, but if I do nothing for a week or two, the Alk drops below 7 and the Ca. continues to rise. So something must be done.


Please correct me if I am wrong, it is my understanding there are three ways to adjust the amount of enriched effluent that comes out of my reactor:
1) Increase flow rate in the reactor (read that the faster the flow rate simulates a higher reactor, therefore more enrichment to effluent at a given pH)

2) Decrease the pH, (all things equal, lower pH means more enrichment of effluent)

3) Adjust flow rate of effluent, at a given pH the faster the effluent leaves the reactor, the more enriched the effluent will be.


Should I lower effluent rate further? Too low could cause lines to clog up, right?

Should I turn the reactor off (or the CO2 off) at night? Can I prgram APEX to turn off at night, but to turn back on if CA or Alk drop to a certain level?

Should I raise the pH over 6.8? I figure I am borderline right now, though if the pH meter is out of calibration significantly, that could be an issue too.


Background:
350 gallon tank
RO Varios CR220 Calcium Reactor w/Two Little Fishes Media (i think)
Reactor pH 6.78 to 6.88 over the course of 24 hours, Neptune double junction pH probe
tank pH 8.02 to 8.05, Neptune double junction pH probe
Drip Rate 10ml/minute (peristaltic pump)
Flow rate in reactor set to 2 of 5 (DC pump with variable speed, no idea what 2 is flowrate but it is the second to last, and the last setting in the "normal" flow rate)

Current measurements of water (measured by recently calibrated trident):
Ca 493
Alk 7.45
Mg 1350
*I know the trident isn't super accurate, but I am shooting for stability only and would like Alk between 8 and 9dkh.
 

lapin

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I would use Randys recipe and dose the Alk part to bring it up. The reactor should keep it stable once your tank settles in


ALso a quote:
Keep in mind that calcium reactors release calcium and carbonate ions (alkalinity) in a fixed and constant ratio (stoichiometric). When CO2 is used to dissolve the selected material, either aragonite, calcite, ARM or any other form of calcium carbonate, are released 10 ppm of Ca and 0,5 meq/l of CO3 (1,4ºdkH), this invariable ratio permits not to be necessary to test more than one of the two parameters (if we know that the carbonate risen a certain amount, we will automatically know how much the calcium has risen).

Effluent alkalinity is adjusted by the CO2 supply rate

According to the product being used it will be advisable to fix a different pH setpoint; for example aragonite can dissolve perfectly with a pH of 6,7 while other stuff such as dolomite (that also incorporates magnesium carbonate) or ARM require a significantly lower pH. Fixing the pH setpoint we fix the rate at which the product is dissolved, but we should not start with very low values because we risk blurring the water in the reactor (which will make a very abrasive mud accumulating on the pump rotor, accelerating its wear); it is therefore advisable to start with pH values slightly higher and lower it until getting a good response in time.

No matter the mineral product we choose, We must aim for an alkalinity in the effluent water ranging between 30 and 40ºdkH. As a starting point we will adjust the valve to produce CO2 at a rate of 1 drop per second. The mineral product used in the the reactor will need at least 24 hours to reach a steady state that allows us to test the alkalinity value at the reactor outlet, with some certainty that it will keep constant.

We've surpassed 40ºdkH, just close the CO2 valve a little bit and test again after 12 hours, We are below 30°dkH, we open a little more gas, it is very simple. It is important to keep the alkalinity within this range if we want to optimize the consumption of CO2 and not to waste it.

Aquarium alkalinity is adjusted by fixing the effluent rate

Once we have the calcium and carbonates drip constant and within the range we are interested, it's time to adjust the aquarium alkalinity and calcium level. This is as simple as setting an initial drip (which it is usually about two drops per second) and test alkalinity every day until you get a minimum of three equal values. From this point on, we can consider that our reactor is set up but it is advisable to make regular checks, at least once a week.
Over the time we will feel confident that if the reactor is well adjusted and none of its elements is obstructed, the calcium and carbonates input will be invariable. However, if everything else goes well, corals (and coralline algae) will grow up and increase their uptake, so we must keep on testing alkalinity with some regularity.
 
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Afm32607

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I read Randy's articles on it.

I guess my question is whether there is anything I can do to decrease the output of my reactor further until the tank catches up?

I would think your answer is no, just dose the one part of the two part and be patient.....too much patience in this hobby...
 

costaricareef

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I read Randy's articles on it.

I guess my question is whether there is anything I can do to decrease the output of my reactor further until the tank catches up?

I would think your answer is no, just dose the one part of the two part and be patient.....too much patience in this hobby...
Try this thread. https://www.reef2reef.com/threads/calcium-reactor-control-by-neptune-trident.660576/ It has worked for me. Focus on Alk at the level you want it (8,9,10,11, etc.) and the Calcium and Magnesium should follow suit. You may have to tweak it a little bit, but its the general ideal of a way to manege your calcium reactor with the Apex. Need a Trident though and a Ph probe on your CaRx.
 
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