Ridiculous pH problem...out of ideas

The CA Rx effluent has a pH of about 6.5. Some delay is needed to allow it to degas or stabilize before it gets to the tank. Your funnel is likely doing some of that. The CO2 should be consumed inside the chamber. If excess CO2 is the issue, you may be adding more than necessary. Adding a tube full of bioballs for the effluent to drip through would help raise the pH even more.
 
I had a pH issues also but started using 1/2 saturated kalk in my ATO and now my pH runs between 7.9 and 8.3 with a normal diel pattern. I was to lazy to go to the hassle of bringing in fresh air. I wish you the best of luck but my recommendation would be kalk and a good nights sleep. Oh yes I use 1/2 kalk because it dose with saturated kalk and vinegar (calcium acetate) which doesn't mess up pH and alkalinity as much as EtOH. Ron


I agree that a kalk reactor add on will fix this. Years back when almost everyone was running calcium reactors it was common for large tanks with a large poplulation of acros to run a kalk reactor to help keep ph up and also to add in supplementing calc and alk.

The other benefit is less addition from the reactor effluent, which is what's the main culprit in dropping your ph.
 
An update for posterity's sake. :)

So the gyrations I went through before helped for a while, but slowly pH started spiraling down again, getting back down to 7.65 or lower sometimes. So I added a kalk reactor (Avast Marine, nice unit), run through the top off. The kalk reactor does marvels for pH (easy to keep over 8.0), but has 2 issues for me: it spikes alk pretty quickly (and I vodka dose, so need to keep it below around 9.0), and I'm rate limited by evaporation.

So I settled on running the ATO through kalk only at night, letting evaporation during the day "save up" so it could be leveraged at night. This helped quite a bit with pH at night, but left me in the odd position of having pH during the day run lower than pH at night, sometimes dipping down to 7.7.

I finally looked at the effluent coming out of the Dastaco calcium reactor...and pH was 5.4. This explains a lot, since the Dastaco emits a decent amount of effluent. Dumping it directly into the sump dragged pH down enough to cause me issues (colony STN's overnight, etc.).

I set up an "effluent collector" bucket, and aerated it as a test. First bucket was small, only about a gallon, and aeration while the Dastaco was off was quick and effective (getting effluent pH up to over 8.1), but when the reactor was running the bucket o' effluent pH dropped to around 6.3 again.

So I finally set up a 5 gallon bucket, with a kick *** air disc and pump. That did the trick: effluent pH only gets down to around 7.5 during the day while the CA reactor is running, and using the kalk at night keeps tank pH between 7.8 and 8.0 all day. The only downside is that the effluent bucket is gravity driven, so I have a 5 gallon bucket mounted to the side of my house now. :)

So a couple lessons learned (by me; a lot of you probably already knew this):

- The Dastaco is a great CA reactor for larger tanks, but emits a lot of reeeeeally low pH effluent that can cause issues even on a 400G tank. Didn't have this pH issue on my old 240G, using a standard bubble CA reactor (but I still wouldn't give up the Dastaco).

- A kalk reactor works really well for pH raises, but can be rate limited by your evaporation

- Having to mount a 5G bucket to the side of your house is much easier if you're already divorced. :)
 
So a couple lessons learned (by me; a lot of you probably already knew this):

- The Dastaco is a great CA reactor for larger tanks, but emits a lot of reeeeeally low pH effluent that can cause issues even on a 400G tank. Didn't have this pH issue on my old 240G, using a standard bubble CA reactor (but I still wouldn't give up the Dastaco).

- A kalk reactor works really well for pH raises, but can be rate limited by your evaporation

- Having to mount a 5G bucket to the side of your house is much easier if you're already divorced. :)

What you didn't learn was PH is a brat and will do what it wants to do and you cannot control it Trying to control it with Kalk risks raising the dKH higher than you may want it. What is the dKH of your tank?

Also the ph of the effluent from any reactor is directly related to the amount of CO2 that is injected into the reactor. I have a 180 heavy SPS tank which is using 5 dKH kdaily. I keep up with a Aquamax 3 running at 90 ml/minute with efffluent dKH of 25.
 
Oh, I’m well aware of the issues chasing pH, but when it routinely dips to 7.6 or lower and you start losing patches of montis or acros, you kinda want to do something about it. I’m happy just keeping it above 7.75. And I’m also aware that CO2 is causing the dips, just didn’t realize how low the dastaco effluent ph is. If you’d read the rest of the thread you’d see that I’d battled the CO2 outgassing of the dastaco effluent outlet in a couple ways prior to aerating the effluent itself.
 
What is the PH of the reactor effluent? If you mentioned it in a previous posting, I apologize for missing it.
 
Direct from the Dastaco it measured as 5.3.

Whoa! That is your problem. Reactor ph should never drop below 6.3 and is best at about 6.5-6.7. Below 6.3 your media will turn to mush. You need to do some research on how to set up and tune a calcium reactor. Check out the videos at BRS.

What is your tanks dKH?
 
This is a Dastaco. It’s how they operate. Their controllers run the entire operation, including CO2 feed, water flow, water mixing station, etc. It’s why they cost so much. :)

The media is fine; they provide the media, and it doesn’t turn to mush. I knew they operated differently than most reactors (I’ve had several), just not how differently. Didn’t suspect the effluent pH was so low until recently.

Read the rest of the thread for the history. Tank pH was getting very low at night (7.6, sometimes lower), and I’ve spent a long while putting in measures to fix that.
 
What is the tanks dKH? What is the tanks daily usage of dKH? What is the dKH of the reactor effluent? What is the flow rate of the reactor?

What makes their media better? All media is just old SPS corals

A ph of 5.3 is very acidic,
 
I keep tank dkh between 8.3 and 8.5, 24x7. Alk usage is around 1.5dkh a day and finally climbing; starting to get good growth now that pH and alk are stable. Effluent dkh is between 30 and 35. Their media isn’t crushed coral, it’s a marble mineral, very dense, purer than limestone. And yes, the effluent output is very acidic.

Look, I wasn’t looking for an argument, I was just updating an old thread with some additional information. I’ve finally gotten tank pH where I want it, and the tank is very stable at this point.
 
Look, I wasn’t looking for an argument, I was just updating an old thread with some additional information. I’ve finally gotten tank pH where I want it, and the tank is very stable at this point.

5.3 does seem a bit low - mine runs at 6.0 (dastaco also) - if your at 0.8 bar maybe try closing off the fine adjustment knob some. If you end up alarming you'll need to open it up again, but that might help raise it up some.
It also sends my ph into the toilet also, i run 2 skimmers on co2 scrubbers + a kalk stirrer to offset it.

Also in the mix chamber is that running clear or is it full of bubbles? If there is bubbles & they're working down low in that chamber you need to reposition that black grating/netting in there.
 
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Have you tried adding a second chamber to your Dastaco? Also, how fast are you dripping effluent? You may be able to slow your rate.
 
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