Macro Algae Refugium Issues with Alk and Calcium Please Advise

[Randy Holmes-Farley]

Wow, I didn't know that, so your fear Randy or concern is that suddenly the formate becomes available to the system the alk will shoot straight up.

I do not know. Unlike acetate from calcium acetate or vinegar dosing, formate (which is very close, chemically) is not really widely used by bacteria. Hence the thought by TM that it is used internally by corals and may not ever be readily detected as "alkalinity" in the bulk water.

I speculate that bacteria may fairly rapidly set up shop in the tank to consume the formate, but that is without basis in any sort of study.

 

[hart24601]

Wow, I didn't know that, so your fear Randy or concern is that suddenly the formate becomes available to the system the alk will shoot straight up.

I try and follow all for reef threads and have not seen this to be the case, but Randy is always wise to point out areas of caution.

 

[Russell Casey]

I do not know. Unlike acetate from calcium acetate or vinegar dosing, formate (which is very close, chemically) is not really widely used by bacteria. Hence the thought by TM that it is used internally by corals and may not ever be readily detected as "alkalinity" in the bulk water.

I speculate that bacteria may fairly rapidly set up shop in the tank to consume the formate, but that is without basis in any sort of study.

Thank you for your input and guidance it is appreciated more than you will ever know.

 

[Lou Ekus]

Yes, but I do not know what level of formate is "impactful". A rise of 40 ppm in calcium would mean the equivalent of more than 5 dKH of alk "stored" in formate.

Just for the purpose of clarity, we have NOT seen formate be "stored" in this way. We have also not seen any instances where the formate has "built up" and then facilitated a quick, unanticipated rise in alkalinity at some later date.

 

[Randy Holmes-Farley]

Thanks Lou.

Given that, why not measure dosing based on alkalinity 24 h after last dose?

 

[Lou Ekus]

Thanks Lou.

Given that, why not measure dosing based on alkalinity 24 h after last dose?

That "might" indeed work. However, I'm still not sure that we can say with 100% certainty, that 100% of the alkalinity added will always be detectable in that time frame. This is something that we are still studying in great detail.

The more important reason though, is that many people are using APEX/Trident and/or Alkatronic or KH Director for the monitoring and adjustment of the alkalinity, and generally those devices do not have a delay of 24 hours available in the programming, for adjustment after dosing. So adjustments will get made before the results might be 100% valid.

 

[Russell Casey]

Thanks Lou.

Given that, why not measure dosing based on alkalinity 24 h after last dose?

Randy great question I am hopeful Lou responds. As I have precipitation on my Ulva and on my heaters. I am not sure if it is or isn't formate. My issue is I can't without water changes get the alk to go over 7.5 and be steady. The calcium is no issue.

 

[Lou Ekus]

Randy great question I am hopeful Lou responds. As I have precipitation on my Ulva and on my heaters. I am not sure if it is or isn't formate. My issue is I can't without water changes get the alk to go over 7.5 and be steady. The calcium is no issue.

I would doubt that the precipitation you are seeing is formate. My best guess is that it would be the standard calcium carbonate that will usually show up in those kinds of heat or pressure conditions. If you are using a formate product, and your calcium is staying at your desired concentration, but your alkalinity is not, a periodic small addition of some sodium bicarbonate or sodium carbonate would be my recommendation. That should make up the difference in the alkalinity that you need. It will most likely only be needed in small amounts, and only once in a while.

 

[Russell Casey]

Lou,
That worked alk is finally at 8.5. I was shooting anywhere between 8 and 8.5. I didn't realize that simple baking soda would raise alk so easlily. Randy in other posts and an article on Alk had suggested it but I didn't think to add that with dosing something else. I will try that.

With regard to another tank I have the alk and calc have been wonderful on all in one reef.