Low dkh, high cal and mag

[Betaktical]

I have a 55 gallon reef tank that has been running for about 8 months. I started out using primo RO water from Walmart. Last month I bought an rodi and have been making my own water since. I use instant ocean reef crystals for salt. I have no filtration at the minute (will be setting up a 75 with a sump next weekend) but I do 20% water changes weekly.

My parameters
No3- 15ppm
Po4- 0.10
Mag- 1500+
Cal-490
Ph-7.8
Dkh- 6.9
Test are all salifert

I have been working on getting my po4 down and it continues to drop so that's not what I am worried about.
My question is how is my alkalinity low if my magnesium and calcium are high?
I have read a little bit about dosing and baking soda seems to be the easiest way to go. Another question I have is could I dose with out having and filtration? Thanks


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[mcgyvr]

Step 1 test newly mixed saltwater..
And if the dKH of it is more than 6.9 then something in your tank (corals/ coralline algae,etc..) is consuming alkalinity faster than your are replacing it..
Its very common to have to dose only one (like alk) and not have to dose cal or mag (or just lesser amounts)

Dosing has nothing to do with having "filtration"

Keeping parameters stable is key to a successful tank..

 

[Betaktical]

Ok I will try that next weekend when I make some more water. Anything you would recommend to bring it up?

 

[anthonys51]

IO reef crystal is cal 490 mag 1440 alk 13. So not really sure how your water got down to 6.9. If woukd also have used up some calcium too. Is your salt clumped up. You want to make sure your salt stays in a zip lock dry place. If the salt clumps up your ratio will be off


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[mcgyvr]

^^ yes I agree that something may be off with your test results..
Unless you have a very stocked tank with fast growing corals I doubt your alk is dropping that fast in only a week.. But its possible..

Just make sure you are testing properly..

 

[Betaktical]

No clumps and I mix it for at least a day before I do the change. I thought the same thing too. It should at least be using some calcium and magnesium.. Why would the alk be 13 of the instant ocean saltwater. Isn't that really high?

 

[mcgyvr]

No clumps and I mix it for at least a day before I do the change. I thought the same thing too. It should at least be using some calcium and magnesium.. Why would the alk be 13 of the instant ocean saltwater. Isn't that really high?

Thats what they state it is with a fresh mixed batch of saltwater..
Its not really high but its over the recommended range of 7-11

Its on purpose to raise alk when its lowered from consumption..
Its also one reason some people don't like to use that salt and it can cause more of a swing than some want..

 

[Betaktical]

I've got an api kit too. I guess I'll try that one and see if it's any different.
I've got a diamond goby a banggai Cardinal 2 oc clowns and a wrasse.
Corals are a Kenya gsp a couple Zoas candy cane monti and pocillopora frags. Every one seems to be doing well.

 

[Betaktical]

I've heard good things about tropic marine pro reef salt and thought about trying it out but I've had good luck with the reef crystals and a lot people say they like it. Would it hurt my tank if I switched salts cold turkey like that?

 

[mcgyvr]

Would it hurt my tank if I switched salts cold turkey like that?

The key to a successful tank is stable parameters..
If you can maintain the same parameters with a different salt then its fine..

 

[Betaktical]

Thanks for all the help