PH help please

[glb]

For example my ph is almost never in this range but my tank is fine.

 

[lutmfurl]

just done some tests as follows

ph 8
alk 12
ca 450
mg 1275

since then added 40g mg

 

[lutmfurl]

is it a myth then that mg should be 3x ca. for example ca 400 mg 1200

 

[Pete polyp]

is it a myth then that mg should be 3x ca. for example ca 400 mg 1200

That is the rule of thumb

 

[Randy Holmes-Farley Verified Community Expert]

It isn't a rule that really makes sense. Why should magnesium be low just because calcium may be low.

Just target about 400-450 ppm for calcium and 1250-1400 ppm for magnesium.

 

[Randy Holmes-Farley Verified Community Expert]

just done some tests as follows

ph 8
alk 12
ca 450
mg 1275

since then added 40g mg

Alk should be allowed to lower a bit, but otherwise those are fine.

 

[Randy Holmes-Farley Verified Community Expert]

Courtesy of Chris Brightwell. This is for nanos but it's a good guide IMO.

I cannot even imagine why he gives density units since almost no reefers measure density or even know how to convert it to specific gravity. I hope he knows the difference.

I also think his temperature range goes down too low for a reef. Same for his density.

His iron number is WAY too high, IMO.

 

[Randy Holmes-Farley Verified Community Expert]

also could someone confirm what is considered acceptable and ideal parameters for water (ph, alk, salt, ca, mg, nitrite, nitrate, salinity)

Thanks in advance

There is a sticky thread at the top of this forum where I detail all the parameters and give the rationale. I can't link it easily as I'm on a phone.

 

[glb]

I cannot even imagine why he gives density units since almost no reefers measure density or even know how to convert it to specific gravity. I hope he knows the difference.

I also think his temperature range goes down too low for a reef. Same for his density.

His iron number is WAY too high, IMO.

Thanks for letting me know. I consider you the expert on this!

 

[lutmfurl]

There is a sticky thread at the top of this forum where I detail all the parameters and give the rationale. I can't link it easily as I'm on a phone.

Brilliant thanks Randy.

 

[lutmfurl]

Will keep updates on parameters over the next couple of days.

Ph is now 7.8 at 7am. Lights went out at 9pm, 10 hours ago.

 

[lutmfurl]

Alk should be allowed to lower a bit, but otherwise those are fine.

Should alk lower on its own or do I need to do water change?

 

[Randy Holmes-Farley Verified Community Expert]

If you have growing hard corals or coralline algae, or increasing levels of nitrate, it will decline. Otherwise it may not.
I'd just not add any for a while.

 

[lutmfurl]

6pm ph at 8.05

 

[diablomaster9045]

An alk of 12 is pretty high. I personally shoot for 8.5-9.5.

 

[lutmfurl]

If you have growing hard corals or coralline algae, or increasing levels of nitrate, it will decline. Otherwise it may not.
I'd just not add any for a while.

Thanks Randy. Not added anything for a couple of days now. PH at 8.02 at 10pm, an hour after lights out. Will probably be down to 7.8ish by the morning. Will keep an eye on everything and see how it goes.

How low would you let it go before requiring action?

 

[Randy Holmes-Farley Verified Community Expert]

Unless this is a ULNS SPS tank, I don't think 12 dKH requires action. Don't worry about the pH.

 

[lutmfurl]

My bulbs are 9 months old. They are stock RSM 130d bulbs. How long do they last? If they are wearing out would this effect ph?

 

[Randy Holmes-Farley Verified Community Expert]

Bulbs could impact photosynthesis and photosynthesis impacts pH. Less photosynthesis could lead to lower pH.

FWIW, my metal halide bulbs are several years old.

 

[lutmfurl]

Soda like has arrived ready for the homemade scrubber/reactor