Help me please with raise in alk with water change

[Reefing_addiction]

Ok tank is 75 gal (my guess on actual volume of water)

My alk dropped down to 7.4
I am doing a water change today
Last time I checked alk on fresh made salt water it was 10

So let’s say I change 15 gal or 20% how much would my alk increase over all in my tank?

 

[JaaxReef]

Ok tank is 75 gal (my guess on actual volume of water)

My alk dropped down to 7.4
I am doing a water change today
Last time I checked alk on fresh made salt water it was 10

So let’s say I change 15 gal or 20% how much would my alk increase over all in my tank?

If your numbers are accurate it would jump to about 7.94 dkh with a 20% water change with 10 dkh water.

Where do you normally keep your alk? Might want to consider changing to a salt with lower alk in the future to avoid those .5 dkh swings.

 

[Jekyl]

If your numbers are accurate it would jump to about 7.94 dkh with a 20% water change with 10 dkh water.

Where do you normally keep your alk? Might want to consider changing to a salt with lower alk in the future to avoid those .5 dkh swings.

Or using baking soda in your top off water to keep it steady

 

[JaaxReef]

Or using baking soda in your top off water to keep it steady

I think Kalkwasser might be a more balanced choice in ATO for that purpose since it handles both calcium and alkalinity evenly.

 

[Ippyroy]

Baking soda is a great cheap way to raise the Alk in the new salt water. It doesn't cause precipitation. I personally raise the Alk in my new saltwater to match what I want it to be in my system. I mix a months worth at a time. The salt mix I use is at the correct levels for Ca and Mg but is low in Alk. I test the Alk before doing a WC and add baking soda. You can get a large bag of Arm and Hammer in the pool section of most big box stores for super cheap and it will last for years in most cases. Baking soda also has a minimum affect on PH which is useful when storing the water.

 

[JaaxReef]

Baking soda is a great cheap way to raise the Alk in the new salt water. It doesn't cause precipitation. I personally raise the Alk in my new saltwater to match what I want it to be in my system. I mix a months worth at a time. The salt mix I use is at the correct levels for Ca and Mg but is low in Alk. I test the Alk before doing a WC and add baking soda. You can get a large bag of Arm and Hammer in the pool section of most big box stores for super cheap and it will last for years in most cases. Baking soda also has a minimum affect on PH which is useful when storing the water.

Ah, we have our wires crossed. I think the OP is struggling with new saltwater being too high in alk and causing a swing up. So I was talking about maintaining alk higher in the display through ATO, not buffering it in the newly mixed saltwater.

 

[Jekyl]

Sounds like alk is being consumed faster than it is being replenished. Baking soda in top off would cure that.

 

[Ippyroy]

A .5 DKH swing every week will not affect most corals, unless they are SPS. I wouldn't start dosing anything until it's closer to a full DKH or if you might start missing WCs.

 

[JaaxReef]

Sounds like alk is being consumed faster than it is being replenished. Baking soda in top off would cure that.

I will always make the argument that you should never dose just alk and not calcium or the other way around on a regular basis, a balanced dosing solution such as Kalkwasser in your ATO (Bulk Reef Supply is cheap and great stuff) or going to a two part solution between water changes is a much better long term solution. You will start getting all sorts of imbalances with chemistry if you dose alkalinity alone on a regular basis. A correction on rare occasion is okay, but I would use that as a long term solution.

 

[JaaxReef]

A .5 DKH swing every week will not affect most corals, unless they are SPS. I wouldn't start dosing anything until it's closer to a full DKH or if you might start missing WCs.

Agreed. But we haven’t asked what type of tank the OP has or what’s in it.

 

[Greg P]

Ok tank is 75 gal (my guess on actual volume of water)

My alk dropped down to 7.4
I am doing a water change today
Last time I checked alk on fresh made salt water it was 10

So let’s say I change 15 gal or 20% how much would my alk increase over all in my tank?

You can use a Scientific Calculator or simply punch the bold formula below into Google

((60x7.4)+(15x10))÷75=7.92

Or do it on paper;
60x7.4=444
15x10=150
444+150=594
594÷75=7.92

 

[Reefing_addiction]

Ok let me try and answer questions and clarify. Sorry I took a nap!

Agreed. But we haven’t asked what type of tank the OP has or what’s in it.

I run a mix reef. Zoas, a few other softies. Favia, favites, bower, Aussie lord, euphyllia, bunches of gonis, chalice (bunch of lps essentially) most of these are new to the system over the last two months.

Sounds like alk is being consumed faster than it is being replenished. Baking soda in top off would cure that.

I would say your correct.

Ah, we have our wires crossed. I think the OP is struggling with new saltwater being too high in alk and causing a swing up. So I was talking about maintaining alk higher in the display through ATO, not buffering it in the newly mixed saltwater.

My dKH was 10.5 before I went on vacation.(this is basically what it was prior weeks and in between water changes and where I’d like to keep it). Came back the last Monday. Everything in the tank looked good so I decided no water change was needed. I figured I do one this weekend instead. So I usually try and test before a water change and than again a day after a water change. So I can see consumption.

Prior to all the new corals I hadn’t seen much consumption.

 

[Reefing_addiction]

You can use a Scientific Calculator or simply punch the bold formula below into Google

((60x7.4)+(15x10))÷75=7.92

Or do it on paper;
60x7.4=444
15x10=150
444+150=594
594÷75=7.95

Thank you!

 

[Greg P]

Thank you!

You're welcome. Note I edited my post (typo 7.95-7.92) after you quoted it.

 

[Reefing_addiction]

I will always make the argument that you should never dose just alk and not calcium or the other way around on a regular basis, a balanced dosing solution such as Kalkwasser in your ATO (Bulk Reef Supply is cheap and great stuff) or going to a two part solution between water changes is a much better long term solution. You will start getting all sorts of imbalances with chemistry if you dose alkalinity alone on a regular basis. A correction on rare occasion is okay, but I would use that as a long term solution.

Ok I actually think I have some of that. And this will help maintain calcium and dkh?

 

[Reefing_addiction]

You're welcome. Note I edited my post (typo 7.95-7.92) after you quoted it.

I’m going to double check my alk in my fresh salt mix and my tank and plug in new numbers if needed. The big thonged I gathered from reading some post on the board is you don’t want a big upswing in alk? So raising it by .52 should be ok? I think @Randy Holmes-Farley says .4?

 

[JaaxReef]

Ok I actually think I have some of that. And this will help maintain calcium and dkh?

Yes. Kalkwasser is a great solution that helps maintain balanced Calcium, Alkalinity, and also helps maintain high PH.

 

[PeterC99]

Baking soda is a great cheap way to raise the Alk in the new salt water. It doesn't cause precipitation. I personally raise the Alk in my new saltwater to match what I want it to be in my system. I mix a months worth at a time. The salt mix I use is at the correct levels for Ca and Mg but is low in Alk. I test the Alk before doing a WC and add baking soda. You can get a large bag of Arm and Hammer in the pool section of most big box stores for super cheap and it will last for years in most cases. Baking soda also has a minimum affect on PH which is useful when storing the water.

So for 10 gallons of fresh saltwater at 6.5 Alk, how much baking soda would I add to raise to 9 ALK?

Thank you!

 

[Reefing_addiction]

So for 10 gallons of fresh saltwater at 6.5 Alk, how much baking soda would I add to raise to 9 ALK?

Thank you!

BRS has a calculator for that!

Aquarium and Reef Calculators - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

 

[Fishingandreefing]

Make sure you check all the pipes and pumps that there’re not calcified. If they are, clean them! Then slowly raise it up with sodium bicarbonate