I'm at a loss, what should I be aiming for with alkalinity and calcium?

[kdx7214]

I have a 75g tank with a 40g sump and a 20g extra tank plumbed into the system. Total system volume is around 115g. DT has a lot of marco dry rock and 4 large pieces of live rock.

Fish: firefish goby, lawnmower blenny, and a six line wrasse
Coral: gorgonian, gsp, and an unknown encrusting sps that seems to be dying rapidly

Tank parameters:
Temp: 77.0 - 77.3
Salinity: 1.026
pH: 8.18
Alk: varies wildly 6 - 8 dkh
Calcium: 366 ppm
Nitrate: 0
Phosphate: 0

I asked about this before, but now I'm not sure if I was asking the right question. I'm trying to save that sps.

What should I be targeting for numbers? I dose alk at night using a recipe from @Randy Holmes-Farley as posted at ReefCentral. I dose 5ml every two hours overnight, starting after ph drops to lowest night time level. Usually dose 20-30ml per night, depending on ph. I avoid going above ph 8.2. I stopped dosing calcium until I can get the alkalinity up.

I'm working on getting more fish as I'm told there is little to no bio-load in the tank. I've dosed some phyto fertilizer in the meantime to attempt to get nutrients up to a safe level.

What should I be doing here? Am I dosing incorrectly? Not sure why the ph is going up so high.

Thanks

 

[Lavey29]

Well cal is low. Alk is not that bad because NSW is 7 DKH. Your alk number is relative to the salt you mix with. Alk and cal consumption is based on the amount of corals you have and their growth rate. Alk and cal should be dosed in similar amounts. Some choose to run their tanks with alk close to NSW others prefer higher alk for coral growth reasons. Your nitrates and phosphate are bottomed out which will lead to problems too.

Are you testing at the same time each day to check alk?

 

[vetteguy53081]

I have a 75g tank with a 40g sump and a 20g extra tank plumbed into the system. Total system volume is around 115g. DT has a lot of marco dry rock and 4 large pieces of live rock.

Fish: firefish goby, lawnmower blenny, and a six line wrasse
Coral: gorgonian, gsp, and an unknown encrusting sps that seems to be dying rapidly

Tank parameters:
Temp: 77.0 - 77.3
Salinity: 1.026
pH: 8.18
Alk: varies wildly 6 - 8 dkh
Calcium: 366 ppm
Nitrate: 0
Phosphate: 0

I asked about this before, but now I'm not sure if I was asking the right question. I'm trying to save that sps.

What should I be targeting for numbers? I dose alk at night using a recipe from @Randy Holmes-Farley as posted at ReefCentral. I dose 5ml every two hours overnight, starting after ph drops to lowest night time level. Usually dose 20-30ml per night, depending on ph. I avoid going above ph 8.2. I stopped dosing calcium until I can get the alkalinity up.

I'm working on getting more fish as I'm told there is little to no bio-load in the tank. I've dosed some phyto fertilizer in the meantime to attempt to get nutrients up to a safe level.

What should I be doing here? Am I dosing incorrectly? Not sure why the ph is going up so high.

Thanks

Calcium - 400-440
Alk 8-11 dkh
Mag 1300-1330
Temp 77-79

What test kits are you using ?

 

[kdx7214]

Well cal is low. Alk is not that bad because NSW is 7 DKH. Your alk number is relative to the salt you mix with. Alk and cal consumption is based on the amount of corals you have and their growth rate. Alk and cal should be dosed in similar amounts. Some choose to run their tanks with alk close to NSW others prefer higher alk for coral growth reasons. Your nitrates and phosphate are bottomed out which will lead to problems too.

I'm using Instant Ocean reef crystals for salt. I was originally dosing 25ml of both alk and calcium nightly, but when I did that the alk dropped to 6.0 - 6.3.

 

[kdx7214]

Calcium - 400-440
Alk 8-11 dkh
Mag 1300-1330
Temp 77-79

What test kits are you using ?

Hannah checkers

 

[Lavey29]

I'm using Instant Ocean reef crystals for salt. I was originally dosing 25ml of both alk and calcium nightly, but when I did that the alk dropped to 6.0 - 6.3.

You need to dose alk and cal separately to avoid precipitation. I dose alk during the day when corals are active and cal at night when skeletal growth occurs.

 

[MichaelReefer]

I shoot for 8.5 alk and 450 calcium.

 

[vetteguy53081]

Hannah checkers

Any number you need to adjust, do it slowly. Raising calcium levels directly may lower the alk as when the calcium in your reef tank increases, so does calcium carbonate precipitaion which also affects PH

 

[kdx7214]

You need to dose alk and cal separately to avoid precipitation. I dose alk during the day when corals are active and cal at night when skeletal growth occurs.

I've never had a problem with precipitation, but can definitely do calcium during the day. I have to dose alkalinity at night to keep the ph from going bonkers (over 8.2).

 

[kdx7214]

Any number you need to adjust, do it slowly. Raising calcium levels directly may lower the alk as when the calcium in your reef tank increases, so does calcium carbonate precipitaion which also affects PH

Right, I remember reading that in a different thread. Initially that's what I was trying to do, but even very small changes caused rapid changes in other things to the extent that I could never figure out what the heck was going on. If I dose alkalinity and calcium together, my alkalinity drops, calcium drops, and ph skyrockets.

 

[Lavey29]

I've never had a problem with precipitation, but can definitely do calcium during the day. I have to dose alkalinity at night to keep the ph from going bonkers (over 8.2).

Ph doesn't rise at night. It goes down slightly overnight. I use a refugium with light overnight to stabilize PH swings.

What is magnesium?

 

[kdx7214]

Ph doesn't rise at night. It goes down slightly overnight. I use a refugium with light overnight to stabilize PH swings.

What is magnesium?

Sorry, I meant to say that if I dose alk at night the ph goes nuts during the daytime. Accidentally left that part out. I have no idea on magnesium level as I've not been able to afford that checker just yet. I'm on a budget

 

[billwill]

KISS. Look at the back of your salt bucket and write the numbers down. Mimic that. You're not going to have mag swings if you're doing monthly water changes unless you somehow create an ULN system that needs everything dosed separately. Most importantly don't do any of it quickly except for a water change with temp and salinity matching the tank.

 

[Lavey29]

Sorry, I meant to say that if I dose alk at night the ph goes nuts during the daytime. Accidentally left that part out. I have no idea on magnesium level as I've not been able to afford that checker just yet. I'm on a budget

Magnesium is the buffer for alk and cal to keep them stable and help prevent alk swings.

 

[HudsonReefer2.0]

Salifert is a good Mg test kit.

 

[kdx7214]

Salifert is a good Mg test kit.

Thanks, I just ordered one

 

[Randy Holmes-Farley]

I have a 75g tank with a 40g sump and a 20g extra tank plumbed into the system. Total system volume is around 115g. DT has a lot of marco dry rock and 4 large pieces of live rock.

Fish: firefish goby, lawnmower blenny, and a six line wrasse
Coral: gorgonian, gsp, and an unknown encrusting sps that seems to be dying rapidly

Tank parameters:
Temp: 77.0 - 77.3
Salinity: 1.026
pH: 8.18
Alk: varies wildly 6 - 8 dkh
Calcium: 366 ppm
Nitrate: 0
Phosphate: 0

I asked about this before, but now I'm not sure if I was asking the right question. I'm trying to save that sps.

What should I be targeting for numbers? I dose alk at night using a recipe from @Randy Holmes-Farley as posted at ReefCentral. I dose 5ml every two hours overnight, starting after ph drops to lowest night time level. Usually dose 20-30ml per night, depending on ph. I avoid going above ph 8.2. I stopped dosing calcium until I can get the alkalinity up.

I'm working on getting more fish as I'm told there is little to no bio-load in the tank. I've dosed some phyto fertilizer in the meantime to attempt to get nutrients up to a safe level.

What should I be doing here? Am I dosing incorrectly? Not sure why the ph is going up so high.

Thanks

As a general guide, this may be useful:

Optimal Parameters for a Coral Reef Aquarium: By Randy Holmes-Farley

[note: edited on 5/29/2022 to update the nitrate and phosphate sections with higher recommended levels.] One of the main roles of an aquarist with a coral reef aquarium is to ensure that the conditions are right for their tank inhabitants. There are many different attributes of the aquarium...

www.reef2reef.com

 

[Katherine Corals]

My aim points are:
Alk- 8.1-8.3
Ca- 420-440
Mag- 1500
Whats important to take from this, is the "stability" everyone talks about. I try not to let my Alk swing no more than 0.5 in a day. I try and keep the swing even more narrow than that! Calcium and Magnesium, however, is more forgiving.
As big of a swing as you have in alkalinity, I would consider a doser, or dose manually twice a day.
Feel free to check out my build thread!

 

[homer1475]

Are you doisng soda ash, or sodium bicarbonate?

Soda ash raises PH, while bicarb has a slightly lowering effect. Might want to switch to bicarb so you don't have the wild PH swings.

 

[kdx7214]

Are you doisng soda ash, or sodium bicarbonate?

Soda ash raises PH, while bicarb has a slightly lowering effect. Might want to switch to bicarb so you don't have the wild PH swings.

I'm using baking soda that has been baked in the oven. Not quite sure which that is, to be honest.