Chasing pH?

[blaxsun]

So a bit of background... I have a Red Sea 200-gallon system that's been online since May (<6 months) and I've recently started having to dose quite a bit more alkalinity than I have at any point in the past (at least more for me, anyway). Current Apex parameters:

Temperature: 77.5-78.5°F
Salinity: 34.6-35.0
ORP: 397-432
pH: 7.8-8.04
Alkalinity: 7.5-8.5 dKH (currently 7.37)
Calcium: 503ppm
Magnesium: 1476ppm
Nitrates: <5ppm
Phosphates: <0.05ppm

Separate Hanna and Red Sea tests conducted every few weeks indicate the Apex numbers are within ±2.5-5%. I'm currently dosing (daily) 48ml of Nyos alkalinity (which has increased from about 24ml over the past few months), 8ml of Nyos magnesium and no calcium whatsoever. My calcium fluctuates between 480-520ppm without really doing anything (when I test every few weeks I'll usually perform at least several digital and titration tests to rule out user error as much as possible). I've adjusted the alkalinity dosing so that more is being received during peek hours as well.

My tank is basically stock, running a protein skimmer, 57-watt UV and pair of reactors (in addition to some bio media). No refugium. I have an air exchange system in my house and recently did my semi-annual cleaning and filter replacement along with the furnace, so I have great air flow. I haven't really noticed any positive or negative changes to my tank, one way or the other.

I tried 500ml Seachem Liquid Marine Buffer about 2 weeks ago based on another recommendation, and for about a week or so the pH increased to between 7.95-8.1, but has since dropped back. It's entirely possible I need to recalibrate my Apex pH probe, and I'll be doing that in the next few days along with verifying against a Hanna pH tester. Otherwise, all the fish, inverts and corals are fat, healthy and thriving and I'm not having any issues.

So my question is this: Other than calcium being slightly higher than I'd like (which I'm trying to remedy slowly with water changes), how are my levels and pH? Am I needlessly concerning myself with "chasing pH" or should I just leave things as is and not really be overly concerned about it?

 

[Dannyboy402]

I wouldn't chase it too much. As long as the Ph is stable you should be good to go.

 

[Gtinnel]

Your pH seems a little low but not even close to low enough to worry about. You said yourself everything in the tank is doing good so clearly your pH is fine.

 

[arking_mark]

It takes 142ml of Nyos alk to raise 200gal by 0.5dKH. This means you are supplementing 0.17dKH per day (which is very, very little). It will take roughly a month and a half to three months to start to see an imbalance with Calcium as these hobby test kits are very inaccurate for Ca.

For most practical purposes Alk/Ca are consumed equally in a tank.

Additionally, Nyos Alk is just Sodium Bicarbonate. So along with the Alk (Bicarbonate) your are adding Na ions to your tank and slowly changing the Sodium balance away from the artifical salt levels that try to replicate natural sea water.

You may want to consider using a balanced approach to dosing that doesn't impact the ionic concentrations over time.

As Na is so prevalent in the NSW and ASW...it would take quite a while to effect the balance. So just something to think about.

 

[blaxsun]

It takes 142ml of Nyos alk to raise 200gal by 0.5dKH. This means you are supplementing 0.17dKH per day (which is very, very little). It will take roughly a month and a half to three months to start to see an imbalance with Calcium as these hobby test kits are very inaccurate for Ca.

For most practical purposes Alk/Ca are consumed equally in a tank.

Additionally, Nyos Alk is just Sodium Bicarbonate. So along with the Alk (Bicarbonate) your are adding Na ions to your tank and slowly changing the Sodium balance away from the artifical salt levels that try to replicate natural sea water.

You may want to consider using a balanced approach to dosing that doesn't impact the ionic concentrations over time.

As Na is so prevalent in the NSW and ASW...it would take quite a while to effect the balance. So just something to think about.

Thanks for this (and to everyone else for the suggestions and comments). In terms of the "balanced approach", what would you propose?

 

[Pistondog]

Removing co2 in the water raises ph. Have you tried increasing light period to increase photosynthesis?

 

[blaxsun]

Removing co2 in the water raises ph. Have you tried increasing light period to increase photosynthesis?

My light schedule currently runs for a 12-hour period. I've considered a co2 scrubber, but I don't have a lot of room in my sump currently and I'm reluctant to invest in another expense.

 

[arking_mark]

Thanks for this (and to everyone else for the suggestions and comments). In terms of the "balanced approach", what would you propose?

Thanks for this (and to everyone else for the suggestions and comments). In terms of the "balanced approach", what would you propose?

Loaded question as there are many options and your tank is barely consuming Alk/Ca yet. So it's hard to say what's best for your situation.

Personally, I drip Kalkwasser and dose All-for-reef. Kalkwasser gives me balanced Alk/Ca with a nice pH boost and All-for-reef is an ionically balanced additive with Alk/Ca/Mag, the key trace elements/ions, and a carbon source.