Basic Dosing questions

Treefer32 · May 30, 2019

A few things up front. I've got a 350 gallon display that's been operational 6-7 months now. I was up to 19 fish, when I didn't know it at the time, but a heater malfunctioned and I lost 14 fish to electroshock therapy. I have 3 fish left that survived. So, I'm done with fish for a few months. Just need to let things stabilize on that side of things. So, I'm building up corals. I'm up to 30 frags in a 350 gallons of system water. Calibrated refrac says 1.025, Ca is maintained at 400 (Red Sea), MG is at 1360 (Red Sea Pro), Alk is at 9.4 (Hanna CHecker).

I'm running an algae turf scrubber (Turbo Aquatics) and a Diablo DC Skimmer rated for 500 gallons. PH is between 8.1 and 8.3 on a daily basis. I do 10 % water changes twice a month. Which, based on my coral growth, the water changes will most likely not be enough to sustain alk and Ca. Alk is 8.0 now between water changes. The day after a water change is back up to 9.4. I'd like that to remain stable throughout the two weeks. I have a buggle magus dosing system with three dosing pumps.

On previous systems I just used Calcium Chloride from BRS and unbaked Baking soda. Which, did fine, but I didn't try for nice coral colors and the rigorous requirements to make sure corals have what they need to both be healthy, colorful, and grow. So, with that said, what would be a really good dosing 2 part or 3 part - Calk, and MG. to maintain the chemistry needed for corals between water changes. I don't have enough to require dosing trace elements between water changes, but, in a year or two I may. I've got around 25-30 frags. Several of the frags have doubled in size over the last 2-3 months. So, I feel I've done something right, but want to keep it going.

In short, best / easiest 2-part suggestions for light dosing between water changes, then can be increased or ramped up as corals consume more? And is difficult to overdose? (or easy to know how I'm impacting the tank. Easy to calculate if how much to use between water changes etc.)

Ron Reefman · May 31, 2019

Almost anything you use to dose alk, Ca and Mg can work. I had a 450g system and dosed Dowflake for Ca, pool supply soda ash for alk and a mix of Mag Flake and Epsom Salt for Mg. My lps corals grew like weeds. I had a hammer coral that was the size of a soccer ball and a Hollywood Stunner (super fast grower) that was bigger than a diner plate. I wouldn't worry too much about which 2 or 3 part system you use.

As for dosing between water changes. So changing 35 gallons of water in your 350g tank (do you have a sump and/or refugium?) and your alk goes from 8.0 dKH to 9.4 dKH? That's a huge jump! You need to test the new water for parameters before you do the water change. In order for 350g of water to go from 8.0 to 9.4 with just 35g of new water, the new water would have to have alk at crazy high levels.

Knowing the parameters of your new water is your first priority. Knowing the tank parameters just before and again just after the water change is your second priority. And telling us the total water capacity of your system is critical if we are going to offer help. If the tank is without a sump or refugium, then the 350 number is good.

I'll follow this thread and try to help.

Treefer32 · May 31, 2019

Thanks! Great thoughts! I have a 75 gallon tank drilled as a sump (with baffles). Skimmer Section, return section, and an algae turf scrubber (sets on top of the sump). External return pump, and about 40 feet of plumbing in total between two return lines and 2 overflow lines.

Plus the tank itself is around 340 gallon with around 150 pounds of rock and 160 lbs of sand. I'm not sure on the displacement but with the sump a little over half full. I'd say 40 gallons there, plus, a few gallons in the plumbing, and say the display has around 300 gallons or just under. That's around 350 total system volume. And I have a 42 gallon brute trash can I use for salt water.

I haven't tested my last batch of salt water. But I see your point. The thing that complicates it is I've had a couple accidents where my Skimmer overflowed a 6 gallon bucket (that I have it drain into it) in small increments throughout a day. Which then was replaced by fresh RO water. Based on how much RODI water was left in my top off bin, I'd say about 20 gallons got changed out of fresh water replacing salt water. Which reduced my salinity and reduced my calcium and alk. Which, meant I had to mix a higher concentration of salt water to get my salinity up. (Significantly higher.. it took 15 cups of IO Salt to get the tank from 1.022 to 1.025) Which threw my consumption of alk off. I wasn't trying to get a feel if dosing unbaked baking soda from Costco and caclium Chloride from BRS is sufficient to offset what the salt doesn't replace with the assumption that I'm not having salt water replaced by freshwater between water changes... (except for normal topping off.)

Ron Reefman · Jun 1, 2019

Treefer32 said:
Thanks! Great thoughts! I have a 75 gallon tank drilled as a sump (with baffles). Skimmer Section, return section, and an algae turf scrubber (sets on top of the sump). External return pump, and about 40 feet of plumbing in total between two return lines and 2 overflow lines.

Plus the tank itself is around 340 gallon with around 150 pounds of rock and 160 lbs of sand. I'm not sure on the displacement but with the sump a little over half full. I'd say 40 gallons there, plus, a few gallons in the plumbing, and say the display has around 300 gallons or just under. That's around 350 total system volume. And I have a 42 gallon brute trash can I use for salt water.

I haven't tested my last batch of salt water. But I see your point. The thing that complicates it is I've had a couple accidents where my Skimmer overflowed a 6 gallon bucket (that I have it drain into it) in small increments throughout a day. Which then was replaced by fresh RO water. Based on how much RODI water was left in my top off bin, I'd say about 20 gallons got changed out of fresh water replacing salt water. Which reduced my salinity and reduced my calcium and alk. Which, meant I had to mix a higher concentration of salt water to get my salinity up. (Significantly higher.. it took 15 cups of IO Salt to get the tank from 1.022 to 1.025) Which threw my consumption of alk off. I wasn't trying to get a feel if dosing unbaked baking soda from Costco and caclium Chloride from BRS is sufficient to offset what the salt doesn't replace with the assumption that I'm not having salt water replaced by freshwater between water changes... (except for normal topping off.)

Happy to try and help. That's a nice big tank. Sounds like you need an alarm in your 5 gallon bucket/skimmer overflow container! ;Wideyed I had very similar issues with my old system which had a big skimmer. I overflowed my a couple of times. Now my skimmer has a float in the collection cup which turns the skimmer off when it's full.

The last line of your post has me a bit confused. You wrote, "I wasn't trying to get a feel if dosing unbaked baking soda from Costco and calcium Chloride from BRS is sufficient to offset what the salt doesn't replace with the assumption that I'm not having salt water replaced by freshwater between water changes... (except for normal topping off.)" Did you mean to say "wasn't" or should that have been 'was'?

Baking soda (baked becomes soda ash) or un-baked is fine to use for alk. I used it for a long time before I switched to a swimming pool supply soda ash just because it was in a 25lb bucket and I was dosing a few drips every couple of minutes 24/7 which did bump up my pH from 7.8 to 7.9. But beyond that, I don't chase my pH level.

Are you currently dosing manually or with a dosing pump?

Randy Holmes-Farley · Jun 2, 2019

Treefer32 said:
In short, best / easiest 2-part suggestions for light dosing between water changes, then can be increased or ramped up as corals consume more? And is difficult to overdose? (or easy to know how I'm impacting the tank. Easy to calculate if how much to use between water changes etc.)

Most any two part will be equivalently easy and fine to use. I'd personally either use a DIY (such as from BRS) or a trusted brand such as ESV B-ionic for a more complete mix.