Alkalinity and calcium problem

[stickman87]

So this is the first time I've used reef crystals and my alkalinity is at 8.4 but my calcium is at 450 and magnesium at 1400 not sure why my alk is so low.. Last week was at 9.2 I do have to use a pH up chemical as my pH is low out if my Rodi unit but has not been an issue using the pH up in the past

 

[beaslbob]

betcha a tab of baking soda will raise the alk and lower the calcium.

 

[Eggpaul]

150 gallon tank. My alkalinity is at 4.5, calcium is 350. 2.5 month old tank. I have 4 fish and a few coral. Salinity is 1.025. I use instant ocean. I have live sand. Should I raise it slowly??

I do have some green hair algae, wonder of that is keeping it low.

 

[Randy Holmes-Farley Verified Community Expert]

So this is the first time I've used reef crystals and my alkalinity is at 8.4 but my calcium is at 450 and magnesium at 1400 not sure why my alk is so low.. Last week was at 9.2 I do have to use a pH up chemical as my pH is low out if my Rodi unit but has not been an issue using the pH up in the past

First, that `set of parameters is perfectly fine. There's no need to raise alk. 8.4 dKH is not low. If you still want to, baking soda is a fine way.

Do not use chemicals designed to boost pH because they necessarily are alkalinity additives, and will boost alk and generally not solve a pH problem.

pH from a properly functioning RO/DI is never, ever the cause of low tank pH.

 

[Randy Holmes-Farley Verified Community Expert]

150 gallon tank. My alkalinity is at 4.5, calcium is 350. 2.5 month old tank. I have 4 fish and a few coral. Salinity is 1.025. I use instant ocean. I have live sand. Should I raise it slowly??

I do have some green hair algae, wonder of that is keeping it low.

You sure it is 4.5 dKH (low) and not 4,.5 meq/l (high, like starting IO often is)?

If it is low, then boosting both it and calcium is a fine plan. I'd use a two part system.

 

[Eggpaul]

You sure it is 4.5 dKH (low) and not 4,.5 meq/l (high, like starting IO often is)?

If it is low, then boosting both it and calcium is a fine plan. I'd use a two part system.

I tested many times with salifert and the ml was at .70, and the chart shows 4.5 dkh or 1.59 meq/l. Api test was 6 dkh. What do you think? I have the brs 2 part, I can raise it slowly.

 

[Randy Holmes-Farley Verified Community Expert]

I tested many times with salifert and the ml was at .70, and the chart shows 4.5 dkh or 1.59 meq/l. Api test was 6 dkh. What do you think? I have the brs 2 part, I can raise it slowly.

0.7 mL was added, or 0.7 mL remains? Some people read the syringe and chart backwards. The more you dispense before getting to the endpoint (the color change), the higher the alk is.

 

[Eggpaul]

0.7 mL was added, or 0.7 mL remains? Some people read the syringe and chart backwards. The more you dispense before getting to the endpoint (the color change), the higher the alk is.

I know what you are saying, but no, it was read correctly. The lowest part of the black rubber was at .70 when the color changed to pink.

 

[Randy Holmes-Farley Verified Community Expert]

I know what you are saying, but no, it was read correctly. The lowest part of the black rubber was at .70 when the color changed to pink.

So you dispensed less than half the syringe of fluid?

An alk of 4.5 dKH is extremely unusual and I'd double check somehow before believing it.

 

[Eggpaul]

So you dispensed less than half the syringe of fluid?

An alk of 4.5 dKH is extremely unusual and I'd double check somehow before believing it.

When I get home I'll post the test with pics just to make sure. I even used the 6.7 dkh test fluid to make sure and it was spot on.

 

[lapin]

Wow you must have some very very very soft water. Where in the world are you located?

 

[Eggpaul]

Wow you must have some very very very soft water. Where in the world are you located?

Sierra madre, Ca. It's a small town next to large cities but it has its own water supply. I didnt have this issue when I lived a few minutes away in Pasadena.

 

[Randy Holmes-Farley Verified Community Expert]

If the alk is really that low, baking soda is the best bet to raise it.

 

[Eggpaul]

Can I just use the BRS soda ash? I have it mixed already. I put in 100ml last night (slowly), so when I test it today it will be a bit higher.

 

[Randy Holmes-Farley Verified Community Expert]

Can I just use the BRS soda ash? I have it mixed already. I put in 100ml last night (slowly), so when I test it today it will be a bit higher.

Yes, but you'll have to add it more slowly to avoid an excessive pH spike.

I'd boost 0.5 dKH, twice a day for several days.

 

[Eggpaul]

Here is the starting point. Black rubber at 1.0. End point was .67. I had added 100ml soda ash. It raised dkh from 4.5 to 5.0. Will keep raising like you said.

Question. Will I have to test water changes and if needed raise the dkh with soda ash also?

 

[Randy Holmes-Farley Verified Community Expert]

OK, so I can't be sure the kit is working right, but that is what the kit says is 4.5 dKH.

 

[Randy Holmes-Farley Verified Community Expert]

Any salt mix should have alk of 7 dKH or higher, so dosing after a water change should not be needed.

 

[Bpb]

So this is the first time I've used reef crystals and my alkalinity is at 8.4 but my calcium is at 450 and magnesium at 1400 not sure why my alk is so low.. Last week was at 9.2 I do have to use a pH up chemical as my pH is low out if my Rodi unit but has not been an issue using the pH up in the past

If you’re keeping a lot of stony corals and run low nutrient levels (nitrate undetectable to say around 1 or 2 ppm, and phosphate from 0-0.02) some may even say your alkalinity is HIGH

 

[Eggpaul]

OK, so I can't be sure the kit is working right, but that is what the kit says is 4.5 dKH.

But the 6.7 dkh test regent was spot on.