Condensate in skimmer air line

[pluikens]

In an effort to increase my pH, I started to use a CO2 scrubber to pull air through into my skimmer. Because of where I placed the scrubber, I got much closer to an exterior wall so I decided to save on soda lime by adding a short run of tubing which pulls in air from outside. So now 3 feet of 3/8 tubing runs from outside to the CO2 scrubber and then another 4 feet of tubing runs from the scrubber to the skimmer. The issue I'm having is that the tubing from outside runs right along an A/C vent which is cooling the fresh summer air and causing water to collect in the tubing. At first, it looked really cloudy (literally a cloud) but over a day or two, enough water starts to collect in the hose that it bubbles and has even cut off the air supply to the skimmer. I also think the soda lime may be getting too wet an affecting the efficiency of the soda lime as my pH hardly gets above 7.8. My proposed solution for this is to get another BRS canister and barb fittings like the CO2 scrubber and place this before the CO2 scrubber. I was initially thinking of running it with no media but just having it in front of the A/C vent so the incoming air would be cooled and the water would be collected at the bottom of the canister for regular removal. Thinking about it more, I know this is done for compressed air systems for air tools so I looked into how they do it. One method is the cooling and separation, my original plan, but other methods are by chemical and hygroscopic absorption. Chemical absorption methods would commonly be by running the air past either sodium chloride or sulfuric acid. Neither of these interested me. Another option is the hygroscopic absorption so running the air by a desiccant like silica gel.

My question is: Are there any dangers or concerns about running the air for my skimmer through a canister filled with silica gel beads? Specifically looking at https://www.amazon.com/Premium-Oran...TF8&qid=1529897524&sr=8-6&keywords=silica+gel which can be regenerated quite easily in the oven. The moisture is in the air no matter what so I should be able to dry it as soon as it enters the house before it gets a chance to really cool down, right? Should that eliminate the moisture enough so condensate doesn't collect in the tubing between this silica canister and the CO2 scrubber once it's really cooled down?

I don't have a way to avoid going past the A/C vent between my outside air access and the tank or I would have gone around it to eliminate this issue. The thermostat in the house is set to between 69 and 72 degrees depending on the time of day. An IR thermometer registers 50 degrees on the vent.

 

[mich2599]

Why not just use Ph buffer?

 

[pluikens]

I should have mentioned, my alkalinity is 8 dKH and my calcium is 430. I do not wish to change these levels with a buffer. I do not see this as a viable long-term solution and preferred to remove properties (CO2) from my aquarium rather than add things like pH buffer.

 

[Randy Holmes-Farley Verified Community Expert]

Why not just use Ph buffer?

FWIW, a pH buffer is almost never the best way to correct pH issues. It always boosts alkalinity quite a bit, and buffers do not provide the most pH rise per unit of alkalinity added.

In that respect, hydroxide as the way to supplement alkalinity is the best (either limewater/kalkwasser or a two part made with hydroxide). Carbonate is second best, with about half the pH boost.

A reef buffer is usually a mix of bicarbonate and carbonate (mostly bicarbonate, which actually lowers pH a bit) and will have less pH boost than these other choices.

 

[Randy Holmes-Farley Verified Community Expert]

In an effort to increase my pH, I started to use a CO2 scrubber to pull air through into my skimmer. Because of where I placed the scrubber, I got much closer to an exterior wall so I decided to save on soda lime by adding a short run of tubing which pulls in air from outside. So now 3 feet of 3/8 tubing runs from outside to the CO2 scrubber and then another 4 feet of tubing runs from the scrubber to the skimmer. The issue I'm having is that the tubing from outside runs right along an A/C vent which is cooling the fresh summer air and causing water to collect in the tubing. At first, it looked really cloudy (literally a cloud) but over a day or two, enough water starts to collect in the hose that it bubbles and has even cut off the air supply to the skimmer. I also think the soda lime may be getting too wet an affecting the efficiency of the soda lime as my pH hardly gets above 7.8. My proposed solution for this is to get another BRS canister and barb fittings like the CO2 scrubber and place this before the CO2 scrubber. I was initially thinking of running it with no media but just having it in front of the A/C vent so the incoming air would be cooled and the water would be collected at the bottom of the canister for regular removal. Thinking about it more, I know this is done for compressed air systems for air tools so I looked into how they do it. One method is the cooling and separation, my original plan, but other methods are by chemical and hygroscopic absorption. Chemical absorption methods would commonly be by running the air past either sodium chloride or sulfuric acid. Neither of these interested me. Another option is the hygroscopic absorption so running the air by a desiccant like silica gel.

My question is: Are there any dangers or concerns about running the air for my skimmer through a canister filled with silica gel beads? Specifically looking at https://www.amazon.com/Premium-Oran...TF8&qid=1529897524&sr=8-6&keywords=silica+gel which can be regenerated quite easily in the oven. The moisture is in the air no matter what so I should be able to dry it as soon as it enters the house before it gets a chance to really cool down, right? Should that eliminate the moisture enough so condensate doesn't collect in the tubing between this silica canister and the CO2 scrubber once it's really cooled down?

I don't have a way to avoid going past the A/C vent between my outside air access and the tank or I would have gone around it to eliminate this issue. The thermostat in the house is set to between 69 and 72 degrees depending on the time of day. An IR thermometer registers 50 degrees on the vent.

I think the chemical means to dry the air will boost the operating cost a lot, and soda lime works best in humid air anyway.

Is there a way to just tip the hose so it mostly runs downhill and collecting water drains into a receiver container, then on the to soda lime? Something like an empty BRS media reactor. Then you just empty that once in a while, if needed.

Or maybe tip it to drain backwards out of the house?

 

[pluikens]

I think the chemical means to dry the air will boost the operating cost a lot, and soda lime works best in humid air anyway.

Is there a way to just tip the hose so it mostly runs downhill and collecting water drains into a receiver container, then on the to soda lime? Something like an empty BRS media reactor. Then you just empty that once in a while, if needed.

Or maybe tip it to drain backwards out of the house?

Yeah, that is what I was initially thinking of with the second BRS reactor. I'll leave just the canister empty and put in the barbed fittings. I can use the 5" reactor since the soda lime reactor is a 10" and both are sitting near the bottom of my stand. The line will be downhill from the window and then uphill to the soda lime reactor. Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Yeah, that is what I was initially thinking of with the second BRS reactor. I'll leave just the canister empty and put in the barbed fittings. I can use the 5" reactor since the soda lime reactor is a 10" and both are sitting near the bottom of my stand. The line will be downhill from the window and then uphill to the soda lime reactor. Thanks!

You're welcome.
Let us know how it works out.

 

[mich2599]

FWIW, a pH buffer is almost never the best way to correct pH issues. It always boosts alkalinity quite a bit, and buffers do not provide the most pH rise per unit of alkalinity added.

In that respect, hydroxide as the way to supplement alkalinity is the best (either limewater/kalkwasser or a two part made with hydroxide). Carbonate is second best, with about half the pH boost.

A reef buffer is usually a mix of bicarbonate and carbonate (mostly bicarbonate, which actually lowers pH a bit) and will have less pH boost than these other choices.

Okay good to know. Been in hobby for just two months and LFS recommended Ph buffer. That explains why my Alk is a steady 11 Dkh. Does this explain why my calcium is low? It was low at 360 ppm when I tested the water 2 days ago.

 

[Randy Holmes-Farley Verified Community Expert]

Okay good to know. Been in hobby for just two months and LFS recommended Ph buffer. That explains why my Alk is a steady 11 Dkh. Does this explain why my calcium is low? It was low at 360 ppm when I tested the water 2 days ago.

Maybe. What salt mix and salinity? Normal IO has about that calcium level.

 

[Larry L]

Is there a way to just tip the hose so it mostly runs downhill and collecting water drains into a receiver container, then on the to soda lime? Something like an empty BRS media reactor. Then you just empty that once in a while, if needed.

That's what I ended up having to do with mine. In my case the line is coming out of the top of the skimmer cup and it's so humid that water was collecting in the tube on the way to the scrubber, and was eventually getting sucked into the scrubber.

 

[rkpetersen]

Another solution would be to wrap the hose in pipe insulation, at least where it passes by the air from the vent.

As Randy mentions, soda lime loves humid air, in fact you should put a bit of water at the bottom of the cannister when you change the media, so drying the air coming in would be somewhat counterproductive. To answer one of your questions, though, there is no problem with passing air through regenerable silica beads to dry it before sending it to the skimmer; such media is commonly used to dry air before passing it through an ozonizer, which is much more efficient in ozone generation if the incoming air is dry.