CO2 scrubber plus skimmer vs. no scrubber or skimmer at all: what would lead to higher pH?

[blaxsun]

Oh. sorry then. This will have a sump. Reefer 350.

You don't have a lot of real estate to work with there. IMHO, these are priorities to focus on:

* Lighting and heating
* Return pump, including UV sterilizer (important)
* Filtration, including fleece roller (optional), protein skimmer and a reactor for GFO/carbon. As you only have 2 media baskets on the 350, you'll need both for either filter socks or the fleece roller.
* Refugium (optional, but does take up a chamber in your already cramped sump)

Then you have ATO (which you may have to lose to free up space), dosing and any control systems like a Neptune (which has various probes). And last but not least, any bio media such as MarinePure blocks or hexes.

I would be really surprised if you could also fit an algae or CO2 scrubber to this list.

 

[Tim617]

I may not be understanding or maybe missing something but i dont see the point of a supercharged scrubber without the skimmer. I mean i understand if you just dont want the skimmer removing too much doc or trace elements but in that case i would use a skimmer without the cup(or leave the cup on and have a bottom drain on the cup always open to more effectively manage bubbles)

I guess you could build a super co2 scrubber without a skimmer body, but it seems like a skimmer is already designed to do most of what you need.... a container to inject air and have a lot of air contact with water while also containing those millions of microbubbles and preventing salt creep.

It's just that I really didn't want a skimmer.

My question is answered. pH will be higher without a skimmer. By the same logic, even a supercharged scrubber using a air pump and diffusers will lower pH compared to not having them at all.

But the DO fluctuations without a skimmer indicate to me that a skimmer is essential. Game, set, and match unfortunately. Scrubber and skimmer it is.

Thanks everyone!

 

[Tim617]

You don't have a lot of real estate to work with there. IMHO, these are priorities to focus on:

* Lighting and heating
* Return pump, including UV sterilizer (important)
* Filtration, including fleece roller (optional), protein skimmer and a reactor for GFO/carbon. As you only have 2 media baskets on the 350, you'll need both for either filter socks or the fleece roller.
* Refugium (optional, but does take up a chamber in your already cramped sump)

Then you have ATO (which you may have to lose to free up space), dosing and any control systems like a Neptune (which has various probes). And last but not least, any bio media such as MarinePure blocks or hexes.

I would be really surprised if you could also fit an algae or CO2 scrubber to this list.

Well, this is the current plan (including the skimmer).

Remove the filter sock/cup section, and fit the roller filter in. (I so didn't want to do this!)

In the skimmer section, put the skimmer in without the collection cup (so just for oxygenation), and put in a CO2 scrubbing structure with APEX controlled solenoids (third party, as Neptune doesn't make them) so that if pH above 8.3, outside air in pulled in, and if pH lower than 8.2, scrubbed air is used. I plan to hang the scrubber on the wall behind the setup.

In the refugium section: put in the pump for the algae reactor, dosing pipes for Chaetogrow and All for Reef, plus two Xport bricks (Bio and NO3), Xport cubes in a mesh bag, and Purit in a mesh bag. No GFO, but if the Xport Po4 cubes plus the chaeto is not doing it, I will throw in some Phosguard in a bag. The reactor itself will sit in the right chamber along with the chiller.

Then in the last section, one return pump to the DT, one pump for the UV sterilzer, and one pump for the chiller. Will see if I can fit the sterilizer next to the Algae reactor in the chiller section. Will be very tight. I would like to draw the water for the UV reactor and the chiller from the DT though, and return to DT. Plus may want a second failsafe return pump. in which case I will move the chiller and UV return pumps to the skimmer section.

This means I have to get rid of the built in ATO, which is just fine, as it is too small in capacity. I will have a separate ATO on the side of the tank, with a 10 gallon reservoir and a Tunze.

What do you think? This would have been so much easier if I didn't need a skimmer.

All the Neptune stuff I plan to mount on a board and hang on the wall. (This setup won't be in a place where visitors come, this is all my pet project, so wife won't object. )

 

[blaxsun]

I'd try to put in as much as you can at the outset (or at least things that need to be mounted or need custom plumbing), because it is going to be an absolute PITA to try and do some of that stuff after the fact.

 

[HuduVudu]

My question is answered. pH will be higher without a skimmer.

This is simply not true. Not sure where you get this from.

Your PH is (mostly) a function of CO2 in your aquarium. If you room CO2 levels are 1600ppm and you have a low fish load then the skimmer will exacerbate the lowering of the PH. Skimmers don't change air chemistry they simply provide a large surface area for gas exchange and thus water chemistry.

I would do so more research on this topic.

 

[Tim617]

This is simply not true. Not sure where you get this from.

Your PH is (mostly) a function of CO2 in your aquarium. If you room CO2 levels are 1600ppm and you have a low fish load then the skimmer will exacerbate the lowering of the PH. Skimmers don't change air chemistry they simply provide a large surface area for gas exchange and thus water chemistry.

I would do so more research on this topic.

My room will have a higher than outside CO2 load. The skimmer will simply pull that into the water. That would lower pH.

Read the thread that I quoted above. Randy answered to the same effect.

 

[HuduVudu]

My room will have a higher than outside CO2 load. The skimmer will simply pull that into the water. That would lower pH.

Read the thread that I quoted above. Randy answered to the same effect.

And vice versa. Room CO2 plays a huge role.

The skimmer is not what is driving PH. It is the ambient CO2.

You can actually drop the ambient CO2 using a scrubber and raise the PH by using a skimmer to increase the surface area. This allows the CO2 in the tank to outgas.

I don't need to read the article because I understand the chemistry that is involved here.

 

[Rjramos]

Observing this. About to start looking into pH. Getting a pH meter on Wednesday. Never measured pH. I have 2 setups at home both 120 gal systems. Both run with large refugiums loaded with chaeto. 1 has a skimmer, no CO2 scrubber.
2 has been running skimmerless for 8 months now.

 

[Tim617]

And vice versa. Room CO2 plays a huge role.

The skimmer is not what is driving PH. It is the ambient CO2.

You can actually drop the ambient CO2 using a scrubber and raise the PH by using a skimmer to increase the surface area. This allows the CO2 in the tank to outgas.

I don't need to read the article because I understand the chemistry that is involved here.

If you understand the chemistry, then it should be clear that a scrubber+skimmer will still let some room CO2 in thus lowering pH, while *no* skimmer won't let *any* CO2 in, and hence have higher pH. In the thread I quoted, this was the observed behavior. Q.E.D.

Note: Of course, the CO2 that is coming in from surface air exchange remains a constant in both cases.

Anyway, I won't debate this any more.

 

[HuduVudu]

If you understand the chemistry, then it should be clear that a scrubber+skimmer will still let some room CO2 in thus lowering pH, while *no* skimmer won't let *any* CO2 in, and hence have higher pH. In the thread I quoted, this was the observed behavior. Q.E.D.

Note: Of course, the CO2 that is coming in from surface air exchange remains a constant in both cases.

Anyway, I won't debate this any more.

It's a good thing that you won't debate it anymore, because your understanding of what is happening is incorrect.

(CO2)scrubber+skimmer ... RAISES PH not lowers it because the scrubber lowers the CO2 to the inlet of the skimmer. Once again it is the CO2 that is moving the PH not the skimmer. The skimmer is just an accelerant of conditions either way.

 

[Tim617]

It's a good thing that you won't debate it anymore, because your understanding of what is happening is incorrect.

(CO2)scrubber+skimmer ... RAISES PH not lowers it because the scrubber lowers the CO2 to the inlet of the skimmer. Once again it is the CO2 that is moving the PH not the skimmer. The skimmer is just an accelerant of conditions either way.

OK, you pulled me back into this.

Scrubber+skimmer will raise pH compared to just skimmer. No doubt about that, because the skimmer will pull in less (but not 0) CO2.

But explain why it will lower pH compared to no skimmer. Especially since experiments show that it raises pH and doesn't lower it?

 

[HuduVudu]

But explain why it will lower pH compared to no skimmer. Especially since experiments show that it raises pH and doesn't lower it?

Arghhhh. Look it isn't the skimmer that is raising or lowering the PH.

Let's start with the definition of PH:

pH Chemistry (Acids & Bases) - Definition, Calculating pH Value, Videos & Examples of pH Chemistry, With Increase in Temperature pH of Pure Water

pH Chemistry (Acids & Bases) - pH scale shows the range of strengths of acids and alkalis. On this scale, the strongest acid is 0 and the strongest alkali is 14. The universal indicator turns a different colour for all the numbers on the pH scale.

byjus.com

You can say this is a random article on the interwebz but this is the same definition that was used in chemistry when I took it in the 90's.

Essential it is the measure of the amount of acid (H+) or hydrogen ions in a solution. The lower the PH the greater number of hydrogen ions in solution. The higher PH the less the numbers of hydrogen ions in the solution.

What is driving PH in our aquariums? By and large CO2 or more importantly it's disassociated counterpart in solution, carbonic acid.

Carbonic acid - Wikipedia

en.wikipedia.org

This acid is what makes the PH in our aquariums go lower. It fluctuates daily because of photosynthetic organisms resperating (exhaling) it. The activities of these organisms creates the swing in the PH but they do not account for the base from which the PH fluctuates. This comes from the ambient CO2 concentration in the air which runs at about 450ppm in atmospheric conditions.

The amount of CO2 can be elevated or lowered from atmospheric, by using localized effects. One effect that would lower CO2 is using a CO2 scrubber. One effect that would raise it is human respiration in a confined space. Changing CO2 levels locally impacts our aquariums. If we have a party and invite a bunch of people over the CO2 will go up and our tank PH will go down, and if we have a skimmer it will go down faster than if we didn't have a skimmer. If we open the windows (assuming a closed house) the CO2 will go down and the PH will go up, and if we have a skimmer it will go up faster than if we didn't. We can even use a CO2 scrubber to drop the CO2 concentrations to below 450ppm atmospheric. In fact doing this agressively in combination with kalkwasser can push the PH to artificially high levls on the order of 8.5.

All of this is irrelevant of whether a skimmer is present or not. You can use a wet dry or even just vigorious surfuce aggitation to accomplish faster ingassing or outgassing of the CO2, but the amount of CO2 is the primary driver of PH not the methods that facilitate it's movement in and out of solution.

 

[Tim617]

If we have a party and invite a bunch of people over the CO2 will go up and our tank PH will go down, and if we have a skimmer it will go down faster than if we didn't have a skimmer.

All of this is irrelevant of whether a skimmer is present or not.

So you and I are aligned. The pH will be lower with a skimmer than without it, ceteris paribus. Which was my question in the first place. So a skimmer is not irrelevant at all.

Thank you.

 

[HuduVudu]

So you and I are aligned. The pH will be lower with a skimmer than without it, ceteris paribus.

If we open the windows (assuming a closed house) the CO2 will go down and the PH will go up, and if we have a skimmer it will go up faster than if we didn't.

We are NOT aligned. You didn't read the entire quote, and you don't understand what you are saying.

So a skimmer is not irrelevant at all.

A skimmer is utterly irrelavant.

You are laboring under some serious confirmation bias.

As I stated before you need to do more research as to what is happening, because you absolutely don't understand what is going on or what you are saying.

 

[Tim617]

If we open the windows (assuming a closed house) the CO2 will go down and the PH will go up, and if we have a skimmer it will go up faster than if we didn't.

Compared to a closed window, of course. But that's not the question. The question is, if the window is always open, given that there is always some CO2 in the air, what would be a higher pH situation? With skimmer or without?

What do you think?

In other words, compare closed window to closed window, and open window to open window, and in each case consider with or without a skimmer. Don't comapre closed window to open window, which is actually not comparing skimmers, but comparing atmospheric CO2 concentration to indoor CO2 concentration. We all know indoor is higher.

But the objective is to compare with or without skimmer, in the same CO2 situation. Open to open, closed to closed.

A skimmer is utterly irrelavant.

You are laboring under some serious confirmation bias.

As I stated before you need to do more research as to what is happening, because you absolutely don't understand what is going on or what you are saying.

Why go personal?

 

[HuduVudu]

But the objective is to compare with or without skimmer, in the same CO2 situation. Open to open, closed to closed.

If the ambient CO2 in the room is 600ppm and it doesn't change then the PH will be a certain value let's say baseline 8.0. With daily fluctuations from photosynthesis then we will see lows of 7.9 and highs of 8.1. If the CO2 in the room doesn't change then the PH will stay at the 8.0 baseline with the same flucuations over the course of the day. If you add a skimmer the PH will stay at the same baseline of 8.0 with the same flucuations over the day. This will exist as long the CO2 remains at 600ppm. If we then take the skimmer off and the CO2 remains at 600ppm then the PH will stay at the 8.0 baseline with the same fluctuations over the course of the day. If we then add the skimmer back on and the CO2 remains at 600ppm then the PH will be at 8.0 baseline with the same fluctuations over the course of the day.

That is it that is all.

Skimmers simply provide a large air water surface area that is all. Once again they will outgas or ingas atmospheric gradients quickly. If there is no gradient then they don't do anything other than their intended function ... DOC export. The only relevant variable here is CO2. That is all.

 

[Tim617]

If the ambient CO2 in the room is 600ppm and it doesn't change then the PH will be a certain value let's say baseline 8.0. With daily fluctuations from photosynthesis then we will see lows of 7.9 and highs of 8.1. If the CO2 in the room doesn't change then the PH will stay at the 8.0 baseline with the same flucuations over the course of the day. If you add a skimmer the PH will stay at the same baseline of 8.0 with the same flucuations over the day. This will exist as long the CO2 remains at 600ppm. If we then take the skimmer off and the CO2 remains at 600ppm then the PH will stay at the 8.0 baseline with the same fluctuations over the course of the day. If we then add the skimmer back on and the CO2 remains at 600ppm then the PH will be at 8.0 baseline with the same fluctuations over the course of the day.

That is it that is all.

Skimmers simply provide a large air water surface area that is all. Once again they will outgas or ingas atmospheric gradients quickly. If there is no gradient then they don't do anything other than their intended function ... DOC export. The only relevant variable here is CO2. That is all.

In other words, you believe that skimmers do nothing extra for gas exchange beyond surface agitation. Which is empirically not true.

 

[HuduVudu]

In other words, you believe that skimmers do nothing extra for gas exchange beyond surface agitation. Which is empirically not true.

It is not surface agitation it is surface area.

How is it empiricly not true?

You have presented no evidence to the contrary. Which would be difficult because it is established understanding both empirically and theoritically. I am not the only one that understands this. Perhaps if you read the articles I linked then you might get closer to understanding what is happening.

I have shown you the chemistry for it. Which you have ignored. I have my own experience with it. I have seen many many many posts that talk about it and how it works. This is not new nor is it difficult. You are making it that way.

Once again you need to do further research on how all of this works. It is a very important part of how salt water aquariums work and not understanding it will cause you to struggle and fail with your aquarium.

 

[Tim617]

It is not surface agitation it is surface area.

How is it empiricly not true?

You have presented no evidence to the contrary. Which would be difficult because it is established understanding both empirically and theoritically. I am not the only one that understands this. Perhaps if you read the articles I linked then you might get closer to understanding what is happening.

I have shown you the chemistry for it. Which you have ignored. I have my own experience with it. I have seen many many many posts that talk about it and how it works. This is not new nor is it difficult. You are making it that way.

Once again you need to do further research on how all of this works. It is a very important part of how salt water aquariums work and not understanding it will cause you to struggle and fail with your aquarium.

Have you read the thread I linked and the comment by Randy on it? It says that when he experimentally took his skimmer off, pH increased. That's empirical.

The rest of it is again personal.

 

[HuduVudu]

Have you read the thread I linked and the comment by Randy on it? It says that when he experimentally took his skimmer off, pH increased. That's empirical.

The rest of it is again personal.

When I experimentally removed my skimmer for a few months, the main effect was a rise in pH (I dosed limewater and so the tank was typically at a deficit of CO2). In general, it drives the tank toward equilibrium with the air being sucked in. whether that raises or lowers pH (or has no effect) depends entirely on the circumstances of the CO2 level in the tank water relative to the air.

Seriously dude.

This is the thread that you didn't read.

You might want to go back and read it carefully. You don't understand what you are talking about and making an argument from authority especially when the authority isn't you makes you look silly.

Randy has it correct. He (obviously) understands. You do not.

Making blanket rules is no help for you trying to understand the very complicated system you are trying to undertake. Understanding is the key here and you are not doing anything to try to understand. Forcing being right only results in dead inhabitants. I would think that that is exactly the opposite of what we are trying to accomplish in keeping salt water aquariums.