Tank Chemistry Stability order of importance

[scoopsthedog]

I thought I would start this thread and by no means am I anywhere near an experienced chemistry reefer but I've tried to consume as much knowledge and personal experience as possible. I wanted to list what I thought would be in order of magnitude of importance the different parameters you want to keep stable and some thoughts behind it in order to start a discussion. The reality is that the magnitude of importance is probably very small in that so much of this is tied so closely together and different corals have different importances but I thought it would be fun to try.

#1 The No-Nos / tank killers
Ammonia
Nitrite

#2 The must haves- always stable
Salinity - 1.025-1.026 / 35ppm
PH 8.1-8.3*
Temp**
KH 8-12***
* PH may fluctuate at night but stable PH seems to be very important
** Temp actually swings pretty wide in the wild from day / night and times of the year but stability in a small tank system is high importance
*** this one confounds me the most. I don't have experience with SPS but most of what I read shows that KH gets consumed with MG and CA and can vary widely based on salt, dosing, and corals. From what I understand keeping stable is a goal (and depending on coral necessary) but from my experience variations from 10-12 don't seem to affect the tank

#3 For a healthy growing coral
CA -450+
MG-1350+
NO3*- 2-5
Pho* 0-0.03
*depending on low nutrient system and type of coral

#4 Trace elements and feeding
Water changes
Coral feedings

So with my tank I've managed to have stable across the board except:
Pho -.16
KH- 10-12

In fact my CA and MG is 500 / 1450 with no dosing and just water changes weekly.

My NO3 is stuck at zero but I feed the coral daily and mix it up between
Reef Roids
Oyster Eggs
Coral Frenzy
Reef Bugs
Polyp Booster
Ocean Magik

I've seen definite growth and so far no issues from the Pho and KH.

Would love to hear feedback.

 

[Randy Holmes-Farley]

OK, well first correction. lol

Nitrite is never a tank killer in a reef tank. It is not toxic in marine systems (unlike fresh).

It is never worth measuring, unless you just like testing or are fascinated with chemistry.

 

[Randy Holmes-Farley]

Second correction. There is no evidence that day to night pH stability is of any importance, and I'd suggest it is not. Even in the ocean if fluctuates, and in a lagoon, it may fluctuate a lot.

IMO, the concern is generally the low end. I'd prefer to not see it drop below pH 7.8. But many fine reef tanks hit a bottom around pH 7.8 at night and are fine. Corals may grow faster at higher pH, but growth rate is not always a goal.

 

[Randy Holmes-Farley]

I also do not agree with the target values of 450+ for calcium and 1350+ for magnesium. Both are well above typical 35 ppt ocean water, where corals obviously thrive.

 

[scoopsthedog]

I also do not agree with the target values of 450+ for calcium and 1350+ for magnesium. Both are well above typical 35 ppt ocean water, where corals obviously thrive.

Thanks for the feedback. If you have time I have a few additional questions.

At what point would these levels become problems for the tank and what are your thoughts generally on things as follows:

Fluctuations in KH?
High CA and MG?
Mid to high Pho?
Low NO3?

If you had to note top three "tank killers" for newbies what would they be?

 

[Randy Holmes-Farley]

High calcium and magnesium are not generally a problem, unless the magnesium is very, very high (like over 1800 ppm).

Undetectable nitrate can certainly be a problem, but not necessarily for most new reefers.

High nutrients can lead to algae problems, which itself is a problem, but high nutrients don't generally kill corals.

Biological pests are, IMO, the most common tank killers. Dinos, etc.

Fluctuations in alkalinity may be a concern in some SPS tanks (probably not so likely in other types of reef tanks), but IMO, it depends on what you mean. I'm not sure that the same fluctuation of alkalinity every day (say, 9 dKH after dosing to 7 dKH the next day right before dosing), is a concern, while a tank at 7 dKH for an extended period that jumps to 9 dKH could be a stress. It is true that many people who initiate dosing pumps to stabilize the alkalinity claim the tank has improved.