Calcium levels head south

[Mad Reefer]

For some time I have never had a problem with keeping CA at 400 to 450. Use kalkwasser reactor and occasional addition of additives. Recently the growth rate in my 155 has taken off with a 20% increase in new corals. I believe that this has put an added burden on my calcium need. It has recently started to fall, 2 weeks ago it was down to 380 so I added some additives. A week ago it was down to 350 so I read a article I believe in Reefkeeping Mag about CA additives and the use of Ionic balanced ones. So I hit it hard with Kent CB-A and part B 3 days ago. Check the CA levels last night and it looks as though they are still falling.

Did not add anything did water change instead. Is there a chance that I’m over shooting the levels and causing it to bleed itself off instead of stabilizing?

[Fishguru]

Have you checked the calcium reactor to make sure there isnt a problem there, maybe a clogged co2 hose or something. Even a 20$ increase should be recoverable, unless your test strips are bad? Just a couple extra thoughts, are you using a dual chamber reactor? Guru

[jdieck]

Better Late than never.

Are your alkalinity levels also going down? If not check your Magnesium levels. It shall be around 1300 mg/lt to maintain stable calcium in the 400 to 450 ppm.

Another posibility if I assume correctly and you are using a Kalk reactor (Not Calcium Reactor)is, if you are adding the effluent based on the rate of evaporation then your bioload could have exceeded the amount of Kalk added which stayed constant at the previous load. You might have to add more kalk than the evaporation might allow. So I think of the following alternatives: a) continue manual supplementation with Kalk solution, b) Increase evaporation rate using a fan blowing over the surface of the water so more solution is added to the aquarium, c) switch to or add a Calcium Reactor ($$), c) Use a doser pump to feed the Kalk reactor and set up somekind of overflow for the volume added above the evaportaion rate.

Good Luck!

[Mad Reefer]

jdieck,

Thanks for the info you are correct on your evaluation. Have checked the Mg and its at 1325 and increased the kalk drip.

Have got the levels up to 400 but have to add things every day to keep it there.

Is the calcium reactor a better way to maintain Ca levels?

[jdieck]

Calcium Reactors are just another good way to add balanced Calcium and Alkalinity. The benefit is that you do not have to go to the trouble of daily additions of Kalk but with the disadvantage of higher cost, and one more thing that can break.

You will need:
1. means to feed the reactor (Powerhead or tap from your return) about 5 to 50 USD
2. The reactor with recirculating pump at about 250 to 350 USD
3. Optional second chamber (I will recomend it to maintain your PH a little higher and better react residual CO2 or carbonic acid) from 40 DIY to 80USD
4. A PH monitor or controller About 80 USD for monitor or 160 USD for controller)
5. CO2 Addition system (Tank, Regulator, needdle valve and Solenoid) for another 100 to 150 USD.
6. Consumables (Power, CO2 and reactor media) at about 5 to 10 watts of power and 20 to 50 USD in CO2 and media every 6 months)

So you may be talking of an investment of 500 to 750 USD

Also a Calcium reactor may very well maintain your levels but they are not very good at increasing them or correct an unbalance so you have to increase them by other methods (Kalk addition, Two part supplements etc.), also some reactors are tricky to adjust.

A reactor is also balanced addition of Alk and Ca (same as Kalk addition) so If you have and unbalanced depletion of either Calcium or Alkalinity, you will still have to add either a calcium only suplement (Like Calium Chloride) or an Alkalinity supplement (Like Bicarbonate).

Another notable difference with a Calcium reactor versus Kalk addition is that your tank will run at a lower PH (in the range of 7.9 to 8.18). This effect is more notable with single chamber reactors than with those with a second chamber. I have observed that many aquarist keep adding some Kalk despite the reactor to maintain the PH, and even higher alkalinity and higher Calcium levels.

If you already have a good working Kalk reactor I will try to use it first. Are you planning in adding more lights? This may solve your problem as your evaporation most probably will increase and so the addition of Kalk from your reactor.

[Mad Reefer]

I was just going over the list of component that might be needed$$.

I thought I read an article that if you had an imbalance that you should shut the kalk reactor off till the balance was restored?

I just added two more 72" vho's as recent as 2 weeks ago.

I will put a fan on the refugium to increase the evaporation and run the drip into the morning to increase kalk addition.

Is there a measurement that I can do on the reactor to make sure that the reactor is producing correctly?

Thanks again.

[jdieck]

You can meassure the alkalinity of the reactor's effluent. For a saturated limewater solution the Alk can be expected to be around 40 meq/L so it will take a lot of your reagent to test it. I will suggest to dilute the sample with destilled water before testing. It will not be as accurate but you will save on reagents.

You can use one part effluent for three parts destilled water to prepare the sample. Fter testing multiply your readings by four to get the actual alkalinity of the effluent.
Some test kits conversion tables (drops of tritrant to meq/l) may not go as high as required but they have a formula to calculate the conversion if you exceed the table's range.

If you have an unbalance of Alk and Ca I do not think it will correct itself by shutting down the reactor as doing so will just drop both your levels.

Most common unbalances are due to higher alkalinity drop than Calcium due to high or fast nitrification process that generate acids that consume your buffers. Or the opoosite when you have normal nitrification but your calcification is high due to high load of SPS corals and coraline algae growth or because Ca precipitates due to low Mg content.
The process that creates the unbalance will continue to be there even if you turn off the reactor so you will need to intervene to correct it by adding the corresponding "unbalanced" supplement and try to correct the source of the problem.

Note that any changes to any of these parameters is a slow process which needs time to stabilize. I will recommend to wait at least 24 hours before you evaluate the effect of any adjustment.

There are excellent articles you can consult written by Randy Holmes-Farley and by Dr. Craig Bingman regarding Ca, PH, Alk that you can find in this site. They have been a great help in enhancing my understanding.

I'm sure you are in the right path. Each system is different and by experimentation you will find the best solution that fits yours.