Low PH !!

[Marcello Salles]

Hi Randy,

thx for your article about low PH.

After fighting with low PH in my tank i decide to turn my calcium reactor off. The PH in the morning was 7,6 and 8,4 at the end of the day !! The ALk never reach 7KH and was having a lot of job setting the correct flow rate and CO2 injections, calcium reactors its just not for me:mad2: .

I am now using only Bio calcium from Tropic Marin and Kalkwasser at all the replaced water. The KH is now 7 and calcium 400/420 mg all Salifert kits. The PH its still runing low, 7,8 to 8,2 but I have less fluctuations.

I am concerned about the dosage of Bio Calcium. My tank is a 100 gallons packed with SPS corals, but i have to use 10 large dosing cups of Bio calcium daily to keep this values !!

Should i have to worry about any toxic undissolved compunds of this product ?? The major problem of Bio Calcium its realted with higher salinity, but my salinity pinpoint its still running at 49,0 to 50,5 with no great variations. What do you think ??

thx in advance ...

Marcello Salles
Rio de Janeiro - Brazil

[Randy Holmes-Farley]

I don't know about toxic compounds in Biocalcium, but i wouldn't worry too much about it for that reason.

You do need more of something along with the limewater (kalkwasser). A two part additive could help nicely.

To reduce the daily pH swing, raising alkalinity and increasing aeration will help.

I also wouldn't worry about salinity. Just monitor it as you are an be sure that it doesn't get too high.

[Marcello Salles]

Thx Randy for reply,

i mean not any toxic compund in the Bio Calcium, but as using in long term some of the " trace elements " going too high and reaching a dangerous level.

You mentioned a two part additive, but isn´t what Bio calcium is about ??

And if i use this additive should i use only the Alk part ??

Part A isn´t a buffer only ?? Bicarbonate, carbonate and borate ??

Is it ok to use Biocalcium daily and use the part A for Alk together, i mean is it possible to disturb the ionic balance ??

I will put some macroalgae in the frag tank to work as a refugium and invert the photoperiod to see is can help me to keep a more stable PH.

best rgds

from down under
Marcello Salles
Rio de Janeiro
Brazil

[Randy Holmes-Farley]

but as using in long term some of the " trace elements " going too high and reaching a dangerous level.

I'm not sure exactly what they put into Bio-calcium, but the liquid two part additives would not suffer from elevated tace elements if they put in what they claim. I discuss how that works in this article:

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

from it:

"One issue that has confused some reefkeepers, however, is the presence of trace elements. Assuming that these products are actually formulated with every ion such that a true natural seawater residue remained (lets call this the “ideal” product), then it will necessarily contain such ions as copper. Since it has been claimed that copper is elevated in reef tanks,11,12 and is toxic to many invertebrates, reef keepers have wrongly criticized this method as adding more copper. That’s actually not what would happen. Since these products leave a natural seawater residue, and since copper may be elevated in concentration in many reef tanks relative to seawater, then using these “ideal” products will actually LOWER copper levels because when the increase in salinity is corrected, the copper will drop.

For example:



You have copper in your tank at 4 ppb and salinity of S=35.

You add a two part additive that over the course of a month raises salinity to S=36, and raises copper to 4.02 ppb.

Then you correct the salinity back to S=35 by diluting everything in the tank with fresh water, and you get a final copper concentration of 3.9 ppb.

Does this happen in real products and not “ideal” products? I have no idea. But the statement by manufacturers that it contains all ions in natural ratios, including copper, should not be viewed as a concern that it is exacerbating a heavy metal problem.



The rise in salinity of these products over time can be very roughly calculated, though there are several reasons why this calculation is only an estimate. For every 1000 meq of alkalinity added in this fashion (and the matching amount of calcium) these products will deliver on the order of 60 grams of other ions to the tank. In a tank with a low calcification demand (defined later to be 18.3 thousand meq of alkalinity per year in a 100 gallon tank (50 meq/day)) this effect will raise the salinity by 3 ppt per year (compared to a normal salinity of S ~35). In a high demand tank (defined later to be 219 thousand meq of alkalinity per year in a 100 gallon tank (600 meq/day)), the salinity will rise by 35 ppt in a year, or approximately doubling the salinity. Consequently, the salinity should be monitored closely in using these types of additives, especially in a tank with high calcification rates.
"