Control rising ph without completely removing coral?

[MrMuggles]

During my cycle I introduced crushed coral in bags in my sump because we have extremely soft water (<10ppm TDS). This helped get the pH from low 6s to around 7-7.2 and it was pretty stable for a while. Now I’m noticing that it is drifting upward slowly.

Over the last couple days I removed half the coral and added four Indian almond leaves, but pH continues to creep up.

im using precise digital pH pen measurements. Not the API tests.

I’m going to do a couple 5% WC today and tomorrow to see if it will come down more.

i thought about removing the remaining coral but I worry that will leave me without any buffer, such that pH could crash later.

most of my fish would like something around 6.5-7 which I would prefer to maintain.

how do I find a balance? Is it totally counterproductive to have both almond leaves and coral?

-EDIT-
Found some detail in how IALs break down. it sounds like I won’t really see a pH drop for some time, if at all, from adding those. I’ll focus on water changes to lower pH and maybe reduce the coral further

 

[CindiL]

Honestly I wouldn’t worry about the exact PH number as much as a stable PH. I wouldn’t remove the remaining coral for the exact reason you mention.

One thing I should mention though is if your tank is now in the mid to upper 7‘s of PH, you will want to buffer your tap water during your water changes to bring the ph up to match that of your tank to avoid shocking the fish. I like Seachem Alkaline Buffer a lot and used to use it when I had to use RO water in my last house due to really awful tap water.

How much water do you normally change at once? How large a tank?

 

[MrMuggles]

The tank is 120g and I’m currently doing ongoing changes of about 5-6 gallons of water change daily.

I’m able to adjust the ph to match using a bit of coral in a tea strainer.

 

[CindiL]

The tank is 120g and I’m currently doing ongoing changes of about 5-6 gallons of water change daily.

I’m able to adjust the ph to match using a bit of coral in a tea strainer.

Oh ok, with small water changes like that, no worries about the ph. Generally you want to keep the PH difference in the tank from before and after a water change to under .5

 

[MrMuggles]

I read 7.6 pH today, so still slowly climbing even with half the coral removed. I suspect the recently added hornwort is at least partly to blame (just started obvious new growth).

When would You take more drastic action to reduce pH? I’m trying to get a threshold in mind. 8.0?

 

[CindiL]

In every house I've lived in, I have never had an issue even with ph up to 8.2. I think it's more problematic if you are trying to breed fish. What kind of fish do you have? or are you still cycling your tank with ammonia or fish food?

 

[Cherryshrimp420]

What fish do you have? Crushed coral will drive pH to 7.8 so keep that in mind.

 

[MrMuggles]

What kind of fish do you have? or are you still cycling your tank with ammonia or fish food?

I have mostly American cichlids. they’re all still tiny and producing negligible bio load. I suppose my additions of ammonia were holding pH down a bit while the cycle was ongoing though, along with bigger water changes.

Crushed coral will drive pH to 7.8 so keep that in mind.

Oh Thanks I thought the coral stopped doing it’s thing around 7.5

I will try not to worry unless it gets significantly >8.0

 

[mattgirl]

What fish do you have? Crushed coral will drive pH to 7.8 so keep that in mind.

Not in every case. Where it stops actually depends on the chemistry of our water. Crushed coral holds mine at 7.2 No matter how much I have in there it never goes above 7.2

 

[Cherryshrimp420]

Not in every case. Where it stops actually depends on the chemistry of our water. Crushed coral holds mine at 7.2 No matter how much I have in there it never goes above 7.2

It means if put in neutral water it will reach an equilibrium at 7.8. In aquariums, acids are constantly produced so the pH at any time may be lower. Co2 will also affect the buffering capacity so if there is high co2 concentrations the buffering effect stops