dosing

lazycouch · Sep 16, 2020

hey guys, here with a quick question today. I was wondering if there was to come a time where one of your parameters were off, lets say cal alk and or mag, by a good amount how would you approach getting the levels back up.

to elaborate, if calcium tests at a low 350 or 340ppm perhaps 330.. one wouldn’t go ahead and dose straight to 380 or 400ppm right? is there a rule of thumb for getting it back to the right level? such as dose 10ppm a day or such

what about reaching proper levels for alk and mag? hopefully this makes sense to someone hahahahaahaha. thanks !

Ranjib · Sep 16, 2020

Yes., I dont recall exactly, but a brs tv video called this out, the recommended safe increase level. Most veteran sps keepers should be able to tell as well.. Lets see if some one can chime in. #reefsquad.

My rule of thumb has been to spread out most changes over 1-2 months. Most chemical additives also calls out maximum amount you can dose for unit volume of tank.

lazycouch · Sep 16, 2020

Ranjib said:
Yes., I dont recall exactly, but a brs tv video called this out, the recommended safe increase level. Most veteran sps keepers should be able to tell as well.. Lets see if some one can chime in. #reefsquad.

My rule of thumb has been to spread out most changes over 1-2 months. Most chemical additives also calls out maximum amount you can dose for unit volume of tank.

thank you! will try and dig through their vids.. hopefully someone can chime in.

SuncrestReef · Sep 16, 2020

Bulk Reef Supply's online calculator allows you to specify your current parameters and desired levels, then it will tell you how much to dose and if there's a limit on how much to change per day. See https://www.bulkreefsupply.com/reef-calculator

ScottR · Sep 16, 2020

It’s usually worse to increase too quickly as opposed to decrease too quickly. For example with alk, the general rule of thumb is to increase 0.5 a day until you get to your target number. Slowly increasing a number is much safer and it’s always good to test regularly to check that you’re reaching your target number and dosing accordingly.

Ron Reefman · Sep 16, 2020

I really hate to be the outsider view here, but I think although slower change is better, I do fairly big changes every week and have seen almost no issues with my corals (mostly zoas with some other soft corals and a handful of both lps and sps). The sps corals would retract their polyps when I added alk, but they were back out in less than 2 minutes!

I test water parameters every Monday, and every Monday my numbers are roughly Ca at 360 to 380 and alk at 6.5 to 7.5 dKH. I bump those up to Ca at 425 and alk to 9.0 dkh. This is in a 90g tank with a 30g fuge/sump. I use Randy's mix of Dow Flake for Ca and swimming pool supply soda ash for alk.

Although I have only had this tank set up for 9 months, I did basically the same thing in my old 40g tank for over 3 years. And the reason I stepped up to a 90g tank is because my 40g had coral growing all over each other!

This is my 3 year old 40g tank.

nereefpat · Sep 16, 2020

lazycouch said:
is there a rule of thumb for getting it back to the right level? such as dose 10ppm a day or such

what about reaching proper levels for alk and mag? hopefully this makes sense to someone hahahahaahaha. thanks !

Closer to 50 ppm seems to be fine for Ca. I would split it up into a few doses throughout the day.

50-100 is probably safe with Mg, although I have rarely ever had to mess with Mg.

ScottR said:
For example with alk, the general rule of thumb is to increase 0.5 a day until you get to your target number.

That seems to be the general consensus with alk.

Randy Holmes-Farley · Sep 16, 2020

lazycouch said:
thank you! will try and dig through their vids.. hopefully someone can chime in.

The concern with substantial boosts to calcium and magnesium are generally not the ions themselves, but potential impurities in them (such as ammonia in magnesium).

Going slow reduces that concern. There's rarely a need to boost them by more than 25 ppm in a day.

Alk may be different, and going slow may be desirable, but it depends on how low it is and how high you want to take it. 0.5 dKh per day is reasonable, and rarely would higher boosts be desirable.