My pH wars

[Koty]

I am still trying to get my pH above 8.0, but it's not working. I have my skimmer connected to an outside air inlet. I am now cooking the TM B salt to convert it to Sodium carbonate. And my ATO goes through a TLF kalkwasser reactor. My guess is that using a high dose of carbon (TM ElimiNP, 8mls/day to a 110g tank), due to my high bioload, is possibly one of the reasons for the low pH. The best I can get to is 7.8.
So I am left with either using a CO2 scrubber or moving to NaOH instead of Sodium carbonate. My question is, how effective is the scrubber? I am reluctant to use NaOH as it is dosing tubes and grandchildren unfriendly (not necessarily in that order).

 

[mcarroll]

Are you solving a tank problem or chasing a number?

If you aren't solving an actual problem and don't want to chase pH numbers, you can feel free to stand down and let your reef run at its natural pH....your corals will not mind. Also check the accuracy/precision of your pH test.....7.8 might be 8.0....it's very close.

My guess is that you would have mentioned the associated problem if there was one, so IMO go easy on forcing the tank to a different pH than it actually wants.

If you want to keep up the fight....then I'm curious if you've sampled CO2 in the room where the tank is? Getting a CO2 monitor might be more helpful in troubleshooting pH since that's what anchors your pH. CO2 monitors are cheap on Amazon or eBay.

 

[Koty]

Thanks for the reply! My pH meter is 2-point calibrated regularly. I am chasing numbers as well as having a few issues. I run a no-water-change tank, so I have to chase numbers at least to a certain extent. Two of my 3-4 years old gonies seem to be struggling, and I am trying to understand and narrow down the reasons step by step. Also, I have a tank with a heavy bioload, yet I tried to push it and get some of the more delicate Acros. Well, within a few weeks, two are already dead.


The 1st pic shows one dead in the rear and the other that seems struggling.

This one below did not make it as well

The last one seems to be rather happy and is alive

 

[Randy Holmes-Farley Verified Community Expert]

All of the noted processes fight against tank top aeration in a high CO2 environment. It may be worth trying the aeration test to see how bad the indoor CO2 level is:

https://www.reefedition.com/ph-and-the-reef-aquarium/

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.

 

[mcarroll]

Thanks for the reply! My pH meter is 2-point calibrated regularly. I am chasing numbers as well as having a few issues. I run a no-water-change tank, so I have to chase numbers at least to a certain extent. Two of my 3-4 years old gonies seem to be struggling, and I am trying to understand and narrow down the reasons step by step. Also, I have a tank with a heavy bioload, yet I tried to push it and get some of the more delicate Acros. Well, within a few weeks, two are already dead.

As For The Numbers
Maintaining mineral levels for hard corals is not in the same category of things as chasing a pH number. Highly recommended to get a CO2 monitor if you suspect an actual pH problem....it's very hard to track down a CO2 issue just looking at it from your water's pH...try using something like this:

As For The Problems
New frags not making it is sorta different from the 3-4 year old coral you mentioned in text. It might be useful to consider them separately.

3-4 years is enough time to suspect things like flow as becoming a problem....the more that you succeed and the corals grow out, the more they obstruct the flow in the tank. 2-4 years in, it's not uncommon to need to rearrange or otherwise improve flow in a successful reef tank....or else corals start to suffer....cores or bases of corals start losing tissue, etc. Lack of flow makes everything worse if you're a coral.

So I would start with that idea and see if you can improve flow to your older corals.

Posting a full tank shot might help if you want flow suggestions.

New frags could be shocked by the difference from the old tank to your tank, so it's much harder to say their problems are related to the 3-4 year old coral problems. They "might" be related....might not.

Where did the pictured frags come from, and do you know what lighting, flow or nutrient levels were like in their former tank?

It may also help if you can post any significant changes that have been made to the system in the last year or two.