Integrating the Alkatronic, Apex and Dos for stable alkalinity AND pH.

[Brett S]

Well, I think I met with very limited success last night:

As I said above, I had guests staying over last night and that always causes a big pH drop. It looks like I still got the big drop, although it wasn’t as bad as normal. Normally it would get down into the 7.70’s, maybe even as low as the high 7.60’s. This time it looks like it bottomed out at 7.83, which isn’t great, but is still better than 7.68.

I think part of the problem is that I cut back my alkalinity dose significantly at night. During the day I dose 60ml, but at night I dose less than 30ml. It’s configured this way because the alkalinity demand is much higher during the day, but unfortunately the pH demand is higher at night. I could try to balance those numbers out a little and dose additional alkalinity at night which will help with the pH, but at the cost of making my alkalinity a bit less stable.

 

[Brett S]

So, now I’m thinking that I may need to give in and add a CO2 Scrubber to my skimmer. I really didn’t want to, but I’m not sure I have any other options.

I think I’m going to try to set it up with a solenoid valve, though, so the Apex can only turn it on when the pH drops below a certain point. Hopefully that way I won’t burn through too much CO2 media.

I’m thinking that I’ll set it up to start dosing Lye as the pH drops, and if it continues to drop then it will enable the CO2 scrubber.

 

[Reefinmike]

So, now I’m thinking that I may need to give in and add a CO2 Scrubber to my skimmer. I really didn’t want to, but I’m not sure I have any other options.

I think I’m going to try to set it up with a solenoid valve, though, so the Apex can only turn it on when the pH drops below a certain point. Hopefully that way I won’t burn through too much CO2 media.

I’m thinking that I’ll set it up to start dosing Lye as the pH drops, and if it continues to drop then it will enable the CO2 scrubber.

I’ve found the effects take few days to settle in. You may see some improvement from running a flat dosing schedule throughout the day

 

[Brett S]

I’ve found the effects take few days to settle in. You may see some improvement from running a flat dosing schedule throughout the day

I think I’m just fighting a losing battle with CO2. The second day was even worse than the first:

Even though it had been dosing only lie since Friday evening the pH didn’t recover during the day on Saturday and so it dropped even farther on Saturday night. My guests left in the early afternoon today and the pH recovered quite quickly at that point.

Believe it or not, the lye did actually help. Unfortunately I don’t have a screen shot of it, but believe it or not, on previous weekends it would typically drop even lower than that, often going under 7.70 during the low times.

I think at this point my option is to implement a CO2 scrubber, but I’m going to use the apex to only enable it when the pH drops. Hopefully that way I only have to use it for about 4 days a month, which should allow the media to last a while.

 

[Reefinmike]

I think I’m just fighting a losing battle with CO2. The second day was even worse than the first:

Even though it had been dosing only lie since Friday evening the pH didn’t recover during the day on Saturday and so it dropped even farther on Saturday night. My guests left in the early afternoon today and the pH recovered quite quickly at that point.

Believe it or not, the lye did actually help. Unfortunately I don’t have a screen shot of it, but believe it or not, on previous weekends it would typically drop even lower than that, often going under 7.70 during the low times.

I think at this point my option is to implement a CO2 scrubber, but I’m going to use the apex to only enable it when the pH drops. Hopefully that way I only have to use it for about 4 days a month, which should allow the media to last a while.

You’re probably gonna laugh at the idea but hear me out- We’re fighting high co2 levels inside our homes. It gets in the water through the skimmer or surface agitation. Say your reef is built “in wall” style and tightly sealed from inside air. With a “fish room” and fresh air exchange you’d have no problem keeping proper pH right? That isn’t an option for most of us but tight fitting glass lids can significantly reduce the amount of household air exchange. Running an open topped tank in a high co2 environment with a co2 scrubber is like ticking in the wind.

They’re not fun to clean and reduce par a little but modern Led’s are capable of compensating. Evaporation is greatly reduced and more importantly, heat loss is minimized. They also prevent jumpers, reduce household humidity and prevent your fish from splashing expensive lights and electronics. As a side bonus, they do a good job keeping your hands out of the tank.

 

[Reefinmike]

All the pesky CO2 producers were out of the house for a solid 48 hours over Christmas eve and day. It was really neat to see how well the system adapted to the CO2 change. pH spiked well above my normal 8.33 the first evening and sent out all kinds of alerts. Over the next 36 hours; dosing switch to mostly soda ash. Normally it's ~220ml soda ash : ~220ml lye. it switched to ~390ml soda ash : 40ml Lye and pH began to stabilize again. I ordered another Dos for bicarb and will be setting up my ambient co2 sensor in a few days to help predict these rare changes.

 

[Brett S]

All the pesky CO2 producers were out of the house for a solid 48 hours over Christmas eve and day. It was really neat to see how well the system adapted to the CO2 change. pH spiked well above my normal 8.33 the first evening and sent out all kinds of alerts. Over the next 36 hours; dosing switch to mostly soda ash. Normally it's ~220ml soda ash : ~220ml lye. it switched to ~390ml soda ash : 40ml Lye and pH began to stabilize again. I ordered another Dos for bicarb and will be setting up my ambient co2 sensor in a few days to help predict these rare changes.

That’s great. It’s cool to see the system working. I haven’t made too many changes to mine yet. I still have the low pH set to 8.0 because I really wanted to try to smooth out the big dips when people are in the house before I try to raise the PH and smooth it out overall. I didn’t want to raise it most of the time and then have it dip way down every other weekend. But I do have an update to that that I will post shortly

As far as bicarb goes, as I posted above, I really think you might be better off just switching out the soda ash for bicarb, rather than trying to complicate things and dose a third thing. If the pH needs to be raised it can use lye and if it doesn’t need to be raised it can use bicarb. I don’t think the small boost from the soda ash really buys you anything, and might even make the small pH spikes that you are getting even higher. I think dosing bicarb would smooth out your graphs even more as well as be a lot easier to program than trying to dose three things.

On a side note, what are you using for an ambient CO2 sensor and are you intending to connect it to your apex in some way?

 

[Daniel@R2R]

Very interesting discussion! Following!

 

[Brett S]

So as I mentioned above, lye wasn’t enough to flatten out my big pH drop when there were three extra people in the house, so, somewhat reluctantly I ordered the small $35 CO2 scrubber and some media from BRS. I had extra people in the house again, so I connected the CO2 scrubber as soon as they arrived in the evening and let it run overnight and the results are impressive.

This is what happened on the first night last time they were here. (And this was actually with lye which made it even less of a dip than I would normally get)

On the other hand, this is what happened last night with the CO2 scrubber:

It was actually almost too effective. Despite all the extra CO2 in the ambient air, with the scrubber the dip was much less than I usually see on a regular night.

I still need to figure out how to best utilize the scrubber. I have a 24V motorized 3 way valve on order that I’m planning to use with my apex to regulate it, but unfortunately that’s not scheduled to be delivered until Monday, so for this weekend I’m just going to need to manually regulate it by connecting and disconnecting the scrubber.

I’m trying to figure out how to best program the apex to use the scrubber. Initially I was thinking that maybe if the pH dips to a certain point it will start dosing lye, and then if it continues to dip even lower it will enable the CO2 scrubber. But @Reefinmike mentioned this ambient CO2 sensor and now I‘m wondering if that might be a better trigger. When there are more people in the house and the CO2 levels rise then the apex could enable the scrubber without having to wait for the pH levels to dip first.

I’m thinking that I should be able to use lye to regulate my pH most of the time and I should just need to use the CO2 scrubber for a few days a month when extra people are in the house, so I’m hoping I won’t be going through great quantities of CO2 media.

 

[Reefinmike]

That’s great. It’s cool to see the system working. I haven’t made too many changes to mine yet. I still have the low pH set to 8.0 because I really wanted to try to smooth out the big dips when people are in the house before I try to raise the PH and smooth it out overall. I didn’t want to raise it most of the time and then have it dip way down every other weekend. But I do have an update to that that I will post shortly

As far as bicarb goes, as I posted above, I really think you might be better off just switching out the soda ash for bicarb, rather than trying to complicate things and dose a third thing. If the pH needs to be raised it can use lye and if it doesn’t need to be raised it can use bicarb. I don’t think the small boost from the soda ash really buys you anything, and might even make the small pH spikes that you are getting even higher. I think dosing bicarb would smooth out your graphs even more as well as be a lot easier to program than trying to dose three things.

On a side note, what are you using for an ambient CO2 sensor and are you intending to connect it to your apex in some way?

to be honest, I really just wanted an excuse to buy more gear! All it’d take is a third pH monitoring VO to allow bicarbonate control. It’s been a while since i’ve walked myself through the chemistry of it but if I remember right- bicarbonate has essentially no impact on pH(concentration of H ions), carbonate removes one hydrogen ion from solution and hydroxide removes 2 H ions. Since pH is a negative logarithmic scale of hydrogen ions, this doesn’t necessarily mean you’ll see a pH of 8.10 dosing all bicarb, 8.20 with soda ash and 8.30 with a hydroxide. Soda ash definitely has a significant impact on pH though it’s hard to see in our co2 saturated environments.

attached is the co2 meter I bought. The -D is important as it has the display to show you the reading for apex calibration. It links to the apex through the asm module only available through special request for $99. Neptune asks for some details on the sensor you intend to use and I believe there is a waiver of some sort. Likely all just a CYA for anyone wanting to willy nilly plug in anything with a bnc connection. I got my module in the PMK kit when they were on sale last month. Extra temp and IO ports only sweetened the pot!

Your scrubber results are pretty impressive! I’m willing to bet you’ll see a sudden spike in your “alkalinity demand”. Likely the same exact demand if you opened up your limits and dosed lye to attain the same pH. I don’t want to push reckless behavior but I feel you have the wits and gear to safely attain 8.3 pH using lye. Start by keeping your normal dose but switch to lye only. Don’t let the higher than you’re used to number keep you from trying it. It’s not a whole lot different than opening your windows in a nice day

 

[Brett S]

Yeah, the scrubber really did better than I thought and it doesn’t seem to be burning though media too quickly. Even though I’ve been running it for nearly two days now I’m not seeing any purple color at all on the color changing media. If I can limit the scrubber to only running a few days a month then I think media should definitely last quite a while.

I am absolutely seeing increased alkalinity and calcium demand. Yesterday I increased my dosages by 25% and it looks like even that may not be quite enough and I may need to bump it up by at least another 10 or 15%. Of course this has the added benefit of dosing more soda ash/lye, so that should help to keep the pH numbers up as well.

I am definitely going to look at increasing my average pH numbers now. I had been hesitant to do it because of the drops I was seeing during the days that I had extra people at the house. It was already a big swing when they came and I was afraid that if I kept my pH even higher most of the time then the swing would be even worse. But now that I know that I can avoid that swing with the CO2 scrubber then I feel comfortable trying to bump up the pH.

I’m definitely going to consider getting that CO2 monitor. The cost isn’t that bad, even counting the cost of the ASM module and it would be nice for the apex to be able to turn on and off the CO2 scrubber proactively based on the ambient CO2 level, rather than reactively when the PH in the tank has already dropped. I feel like that would help prevent a drop and keep my pH nice and stable.

 

[Brett S]

to be honest, I really just wanted an excuse to buy more gear! All it’d take is a third pH monitoring VO to allow bicarbonate control. It’s been a while since i’ve walked myself through the chemistry of it but if I remember right- bicarbonate has essentially no impact on pH(concentration of H ions), carbonate removes one hydrogen ion from solution and hydroxide removes 2 H ions

Hahaha, one can always use more gear. But here is my thinking on this: During the day the pH will naturally rise due to photosynthesis, so by using soda ash during the day as we are now we are just causing it to rise even more. This is going to cause a peak during the middle of the day when the pH is rising the most. However, if we only dose bicarbonate at that point then the peak should be lower since we are only dealing with the natural rise from photosynthesis. We aren’t forcing it up at all with our dosing. At night when the pH is naturally falling we can dose lye to keep the pH up.

But there’s really not a place where soda ash would be necessary. I suppose in the middle, during the evenings and mornings as photosynthesis is starting up and slowing down and there’s a minimal natural rise then soda ash could be used, but I’m not sure that you can determine that point reactively based on the pH, and frankly, even with just lye and bicarbonate the apex would achieve the same effect by alternating doses. The pH would drop slightly, which would cause a couple doses of lye, which would then raise the pH slightly and cause a couple doses of bicarbonate. But I think the cycle would be very minimal. No more than a pH change of .1 or .2. Frankly instead of using soda ash you could even just configure it to provide a half dose of lye and a half dose of bicarbonate during those times.

And actually, as I’m thinking about it, implementing some time based controls might be the way to do it. Like I said, I feel like it would be very difficult to dose three things based on reaction to the current pH, but we know at what times the the pH is highest, lowest, and in the middle. You could configure it to prioritize bicarbonate during the day when pH is peaking, prioritize lye during the night when pH is lowest, and prioritize soda ash (or just half doses of lye and bicarbonate) during the other times. Of course, it would still be configured to dose the other additives if the pH falls out of range during those times.

Sorry, this post turned into kind of just a stream of consciousness as I was thinking about this, but hopefully it makes sense

 

[Reefinmike]

Haha well, you aren’t wrong in your thinking process. I have a bunch of soda ash to burn uo and it seems to be the right fit for the job with my current co2 “profile”. What’s done is done when it comes to my purchases, I’ll probably just start with using the extra dos for “emergency” situations like i’ve seen over the holidays. I was out again starting 24 hours ago. pH spiked again and the system reacted as expected. Alkalinity began to absolutely tank. Normally it never dips below 9.5. It doesn’t have any signs if an Alkatronic error so I’m thinking my soda ash reservoir ran out the flat top to the peak pH seems to back that up. Alkalinity started to recover as lye dosing re-enabled I’m not too terribly worried about the situation but I’ll be able to see what’s going on here in 8 hours. I suppose if alk starts dropping again, i can just slide my pH low to ON and the system will default to lye only.

Gotta get me some of those DDR “hack” chips to be able to monitor my fluids better.

 

[Brett S]

That’s a big alkalinity drop. Hopefully everything does OK through that. A few months ago I had something similar happen where I ran out of soda ash and didn’t catch it immediately and my alkalinity dropped by a bit over 1dKh. Most of my corals were ok, but my bubblegum digi was not happy. It bleached white and lost a number of it’s branches. It’s taken a couple of months, but it does seem to be recovering. It’s got may 75% of it’s color back. I haven’t seen much new growth yet, but hopefully it will start soon.

 

[Reefinmike]

It sure is and has all the hallmarks of an empty reservoir. Gallon jugs aren’t lasting very long, I aught to switch back to 5 gal buckets.

Fortunately my reef is really resilient. I yolo dumped in 3dkh of bicarbonate 6 weeks back on a hunch and everything handled it well. I have maybe $100 invested in coral and they’re all “junk” species. I’m moving in a few months and really dont want to keep anything but a little green slimer and blue digi. Everything grows way too fast to keep things long term. The slimer and caps were 3” frags when I started this tank last year. My long term goal is a 5+ year acro tank. I’m doing these whacky experiments now to “get it out of my system”

 

[Reefinmike]

Well sure enough the soda ash was empty. Kinda funny to see just how dang dependent my system is on dosing. I turned my pH high VO off this afternoon to limp through with lye dosing the rest of the day. The pH disaster VO triggered about 90 minutes ago when I broke 8.52. It shut off power to the dos and everything worked just as expected. I really need to get some better, larger dosing containers. I could easily make my solutions more concentrated but I’m not too keen on getting the lye much stronger... i’m gonna trickle in 1dkh of bicarb over the next few hours and hopefully get everything back to normal.

 

[Brett S]

Glad that you’re back and getting back to normal. The CO2 scrubber has actually wound up raising my pH a bit more than I was planning. Even though I’ve been trying to regular the use of the scrubber when the CO2 is reaching it’s peak it’s still much higher than it has been.

I was planning to make pH changes more slowly, but at this point I know the CO2 scrubber can help get me through the dips, so I’ll just change the cutoff for it to switch to lye and try to keep it around those levels even after my guests leave on Sunday night and I turn off the CO2 scrubber.

 

[Reefinmike]

Glad that you’re back and getting back to normal. The CO2 scrubber has actually wound up raising my pH a bit more than I was planning. Even though I’ve been trying to regular the use of the scrubber when the CO2 is reaching it’s peak it’s still much higher than it has been.

I was planning to make pH changes more slowly, but at this point I know the CO2 scrubber can help get me through the dips, so I’ll just change the cutoff for it to switch to lye and try to keep it around those levels even after my guests leave on Sunday night and I turn off the CO2 scrubber.

thanks for reporting back your findings as well. the co2 scrubber absolutely works and I'm not surprised you have to chase ever increasing alkalinity demand. with the scrubber you're removing a co2 molecule from the system while lye dosing is turning that co2 molecule into CO3 which is handily what our corals need to grow. just two different ways to go about the same end goal. a co2 scrubber is certainly a better option if the coral load isn't able to handle the alkalinity addition from lye.

I ran my dosing through a calculator last night and found my reef is using 4DKH per day!!! I always knew my demand was abnormally high and attributed it to precipitation despite the fact I've never seen a HINT of build up on heaters, pumps, sand etc. well, running out of soda ash for 12 hours proved that demand is true. alk dropped 2 full dkh.

 

[Brett S]

So I have learned some things today.

Last night my pH dropped considerably more than it had the previous two nights, despite having things configured the same way.

First, I discovered is that I’m actually using more of the CO2 media than I thought. The color change is much more subtle than I was expecting and since the used media turns a light purple and the BRS reactor that I’m using is also a purple color it is very difficult or impossible to see the color change while the cartridge is in the reactor. When I pulled the cartridge out to check on it I discovered that I have actually used about 1/2 of one cartridge worth of media.

What I think happened last night was that even though the media was only half used, what was left didn’t have enough surface area to remove nearly as much CO2 as the full cartridge, so it was much less effective.

We left the house today to take a trip to World Wide Corals and you can see how the pH shot up once everyone had left the house. I did also leave the half used cartridge running because it didn’t occur to me to stop it before I left, so that probably caused it to increase even faster.

Interestingly, I discovered that WWC sells a lot of BRS branded merchandise, including CO2 scrubbers. So I was able to pick up a second scrubber while I was out and I’ll run them in series. That way I’ll be able to allow it to fully exhaust one cartridge and still have a second one to make sure the system can remove enough CO2.

I have also discovered over this weekend that I really do need to allow the apex to control the CO2 scrubber. Since my motorized 3 way valve isn’t supposed to be delivered until Monday I’ve been needing to babysit things and manually enable and disable the scrubber as the pH rises and falls. Once the apex can control it that will make things much easier.

I’m still thinking that I may try to connect an atmospheric CO2 sensor to my apex through an ASM module, as you discussed which would allow me to enable or disable the CO2 scrubber based on the atmospheric CO2 levels, then I’ll do some additional finer control based on the actual water pH levels.

 

[Brett S]

And I just ordered that CO2 sensor from ebay. Its coming from NC, so hopefully it won’t take too long to get here to florida. I also looked through the manual for it and in addition to the 0-5V output that would work with the ASM it looks like it also has a relay output that can be set to trip at a specific CO2 level, so I’m thinking I might just be able to use that with a port on a breakout box.