How important is pH? What I've learned after 25 years of reefing.

reefkeeper2

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BRS Member
So since I'm sitting around waiting for my new tank to arrive (delayed because of covid glass shortage) I've been spending time watching videos from the many online reefers. As you know there are loads of them on YouTube, and you get to see how people from all over the world run their reef tanks. The hot topic now is pH. In the past it used to be "don't chase numbers and don't worry about pH". Personally, I never followed that advise, but I figured it was because I'm just more neurotic than most. So I was pretty surprised to watch Chris Meckley of ACI Aquaculture say that pH was the most important parameter to watch and control on ReefBums latest podcast. And he's not the only one. Boy the times have changed . I'm sure a lot of people are not going to agree with that statement. It's going to take a lot convincing to knock alkalinity off the top of the most important list. But I understood the point he was trying to make.
Some of the effects I've observed when my pH ranged lower is anecdotal. This would be seeing more cyano in the tank and more instances of STN. I always suspected a link but I have no proof. What really convinced me of the importance of keeping pH up was what I saw in my frag tank. I could never understand why my frags did so poorly in the frag tank. The water was tied in to the display and the lights were the same. The only difference was the lights were on opposite to the display. The frag tank was lit at night. I did this to help with the daily pH swing. When I looked hard at it I saw that the corals in the display had a daytime pH that rose to 8.2 and sometimes 8.3. The corals in the frag tank never had a daytime pH that was anywhere near 8.0. Sometimes the pH dipped below 7.8 during the time when they were getting the most light . Every coral that I placed in the frag tank lost color and looked different than the mother colony. Every single one. And the longer they stayed in the frag tank, the more they changed. Since the daytime pH was the only difference between the two tanks, this was proof to me of the importance of keeping pH levels up.
The hard part of this is that I think pH is the hardest parameter to control. I've found that good aeration of both the tank and the room is the best remedy. But that is a lot easier said than done. Venting your skimmer to the outside helps some. An air exchanger for the house would be awesome but pricey. There are CO2 scrubbers but they aren't a good option for larger systems. A refugium on an opposite light schedule can help too. It usually takes a combination of strategies to have a noticeable effect. So if your wondering if your reef would look and do better if you could get your pH up, I would have to say most definitely yes. It's not easy though finding that fix.
 

BiGGiePauls33

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I just started running a pH scrubber as I was barely ever breaking 8.0. I added Jorvet soda lime form www.medvet.com and it raised it as expected but quickly depleted. I then created a recirculating scrubber where I drilled through the top of the skimmer cap, this seems to aid in maintaining 8.1 to 8.3 throughout the day. Once it warms up and I can open the windows, I'll see if I can achieve the same levels.
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Some people run an solenoid, so when pH begins to spike their controller will turn the solenoid on to suck room air and stabilize the pH. I use a cheap plug as I'm always home and it's easy to just remove the cap on the tee.
 

reefkeeper2

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BRS Member
My system was too big for the scrubber solution. I burned thru the media. I never tried recirculating the air but had never heard of it back then. It's good not to have the pH dive to low at night, but I think it's even more important for it be optimal during the day when the lights are on and the corals are trying to grow. Looks like you got it!
 

shrimpchips

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BRS Member
Kalkwasser reactor or dosing through an ATO can help with pH swings/low overall pH.
If you’re dosing using sodium bicarbonate, switching to sodium carbonate (soda ash) can also increase pH. Drawing in fresh air from the outside can help too, especially if the skimmer is located in a high CO2 location.
 

Terry Martin

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BRS Member
The frag tank evidence is interesting. I had same thing with a frag tank at one point. My ph is ok with dosing soda ash and running an outside line to aerate the tank through skimmer. I saw a post not long ago - lost it now - that talked about direct aeration through air pump located outside but didn't say exactly how to do it. Has anyone heard of that? tried it?
 

Terry Martin

Well-Known Member
BRS Member
The frag tank evidence is interesting. I had same thing with a frag tank at one point. My ph is ok with dosing soda ash and running an outside line to aerate the tank through skimmer. I saw a post not long ago - lost it now - that talked about direct aeration through air pump located outside but didn't say exactly how to do it. Has anyone heard of that? tried it?
The other issue is measuring Ph. Keeping a probe well-calibrated is tricky. I don't really trust my apex probe anymore. It registers plausibe daily swings but whether the high/low numbers are accurate??
 

Joe Rice

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It's good not to have the pH dive to low at night, but I think it's even more important for it be optimal during the day when the lights are on and the corals are trying to grow.
This seems quite plausible in which case the practice of turning off a refugium light during the day to even out the pH swings between day and night might actually be counterproductive. I leave my fuge light on 24/7 and my pH varies between 7.9 at night and 8.3 during the day. I don't run outside air to my skimmer but I do have a whole house air exchanger.
 

PSU4ME

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BRS Member
Mine swings 7.9-8.1 and I would like to get it a bit higher but wanna keep it stable. With the sump end in the back room, I’m looking to do an air exchanger in there to manage the smell, humidity and co2.

I think ph is very important
 

Mixed Reefer

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So how do you guys get it so stable. Mine swings wildly each day. A little bit about my setup- outside air to skimmer, soda ash ( bulk reef 2 part), carbon dosing,. My swing is about .15 each day to night. I’ll check in morning it’s usually 8.1 over the course of the day it climbs to a max 8.17
Not sure what’s happening here. Anyone? :)
 

Terry Martin

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BRS Member
So how do you guys get it so stable. Mine swings wildly each day. A little bit about my setup- outside air to skimmer, soda ash ( bulk reef 2 part), carbon dosing,. My swing is about .15 each day to night. I’ll check in morning it’s usually 8.1 over the course of the day it climbs to a max 8.17
Not sure what’s happening here. Anyone? :)

It's not a big swing. I typically have .2 to .3 swings even though i run the refugium at night.
 

PamBrent71

Active Member
BRS Member
I saw a post not long ago - lost it now - that talked about direct aeration through air pump located outside but didn't say exactly how to do it. Has anyone heard of that? tried it?
We do something like this. We have 2 air pumps that send fresh air to the skimmer and to the top of the tank (not IN the water, but as a blanket of fresh air on top of the water). Our fresh air comes in thru the garage - we initially set it up thru a window in that room to prove it worked. But I thought the porch looked kind of junky with the air pumps, extension cords, and air hoses strewn about. So we relocated it. Thankfully we had some 1/2" pvc tubing to poke thru the wall between house and garage, and the silicone air tubing slid thru the tubing.

We use gas for cooking, heating, the clothes dryer, water heater ... so in the winter the CO2 hits 1900 easy. It's more like 1100-1200 now and if windows are open we get down to 600-700. This is the price you pay for replacing drafty single pane windows and putting on new siding, your nice leaky house gets too airtight. I know we waste some heat by pumping cold air into the house but gas is so inexpensive it is a decent trade off (plus ... high CO2 isn't great for humans, either).
 

Terry Martin

Well-Known Member
BRS Member
We do something like this. We have 2 air pumps that send fresh air to the skimmer and to the top of the tank (not IN the water, but as a blanket of fresh air on top of the water). Our fresh air comes in thru the garage - we initially set it up thru a window in that room to prove it worked. But I thought the porch looked kind of junky with the air pumps, extension cords, and air hoses strewn about. So we relocated it. Thankfully we had some 1/2" pvc tubing to poke thru the wall between house and garage, and the silicone air tubing slid thru the tubing.

We use gas for cooking, heating, the clothes dryer, water heater ... so in the winter the CO2 hits 1900 easy. It's more like 1100-1200 now and if windows are open we get down to 600-700. This is the price you pay for replacing drafty single pane windows and putting on new siding, your nice leaky house gets too airtight. I know we waste some heat by pumping cold air into the house but gas is so inexpensive it is a decent trade off (plus ... high CO2 isn't great for humans, either).
Interesting, were you able to measure the difference it caused in ph?
 

this is me

I like turtles
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You should change the light cycle to match with your display. When you've done this and see an improvement, it'll be more credible.
There's lots going on, maybe it's flow in the frag tank not up to par of that in display. Maybe lighting is not same intensity(PAR),etc. etc..
 

reefkeeper2

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BRS Member
You should change the light cycle to match with your display. When you've done this and see an improvement, it'll be more credible.
There's lots going on, maybe it's flow in the frag tank not up to par of that in display. Maybe lighting is not same intensity(PAR),etc. etc..
Don't have a display at present, still waiting for the new tank. Lights were the same so I can't see that as a factor. Flow is great in the frag tank, better than what I had in the display. There are always variables I guess that I might not know of.
This seems quite plausible in which case the practice of turning off a refugium light during the day to even out the pH swings between day and night might actually be counterproductive. I leave my fuge light on 24/7 and my pH varies between 7.9 at night and 8.3 during the day. I don't run outside air to my skimmer but I do have a whole house air exchanger.
A fuge really needs to have a dark period. I've read plants grow better with 6 hours of darkness.
 
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reefkeeper2

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BRS Member
That's right. No display at present. Waiting for new tank. Frag tank looks fine now but I have no display to compare.
 
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