[JanS]

I set this pressurized system up about 5 days ago and started out at 30 bpm, and have been increasing it daily. I've gone to 60, 90, 120, etc. and am now at over 2 bps. I've yet to get the pH below 7.4 with it running 24 hours (it does have a controller). The 7.4 comes at night and then it goes back up again when the lights come on. I'm using the Plant Guild reactor and that seems full of churning bubbles.
I'm also starting to get pearling at the 7.4 pH.

I've checked my KH a few times and it seems to be a pretty steady 7+, so I'm shooting for a pH of 7 or maybe 6.9.

Anyway, is there a point where I could be increasing the bubble rate too much? If so, what would that point be?

Thanks.

 

[Troy Hendrickson]

Hi Jan,

Just out of curiosity, how's your surface agitation?

With a KH of 7 and a pH of 7.4 you approximate CO2 level is around a little over 8. Depending the efficiency of the reactor, I'd say your losing CO2 just a hair slower than your putting it in. a pH o 7 would be a reasonable goal, try bumbing the bubble rate to 3/sec, if you notice bubbles leaving the reactor, try throttling down the pump a bit

 

[Error]

I have heard of massive overnight fish kills with CO2 saturation, but I think it's rare.

My water comes out of the tap at 7.4 and doesn't go down all that much, despite my pressurized system.

Your CO2 reading seems to be about 8ppm at a KH of 7 and a pH of 7.4, if I read the chart correctly.

What test kits are you using?

And what is your filter? Is it an overflow model? Surface agitation might be hurting you.

 

[JanS]

Thanks for the advice.

I have an Eheim 2217 with the spray bar about an inch below the surface of the water (pointing toward the front and slightly downward) and a Whisper HOB which also has the outflow well below the surface since I keep the tank filled to the rim. It doesn't seem to me that that either of them would cause any loss from surface agitation, but maybe I'm wrong too. :? At least I don't see surface agitation, just the plants waving from the circulation.

For testing the pH I'm using the controller, the Tetra pH reagent test and a Jungle quick dip and they all agree. For the KH I'm also using the Tetra test and the dip and read and again both of them agree.

I'll keep trying to bump the bubble count up a bit at a time to see how it goes.
That's helpful to know if it starts losing bubbles out of the reactor, it may be time to limit it.

Here's a photo of the reactor, if that's any help....

 

[Error]

HOBs are inherently bad for tanks that use CO2. Even if you don't see any agitation at the outflow, there is most certainly some inside the filter itself. You can curttail this to a small degree by making sure the removable top is on the filter.

 

[dennis]

Jan,

What size is your tank. I have a 10 gal and a 15 gal that I run pressurized CO2 on. 10 gallon has a whisper HOB and the 15 has a Fluval 104. I inject the CO2 directly into the filter inlet in both cases. The fluval I use a fine air stone to minimize gas build up in the filter and the whisper the bubbles go straight in. Both work fine fo rme. I use a bubble rate of about 1 bubble per 2 seconds. I have no problem maintaining a CO2 levels of 30+ppm. A bigger tank would take more CO2 I am sure

Hope it helps

 

[Daemonfly]

IMHO, that reactor doesn't look like it's working that well - way too much CO2 stuck inside the chamber (have you just doen a water change where water level drops below reactor?). Do you see any bubbles coming out of it then rising to the surface? If so, it's probably too small for the amount of CO2 you have to put through it.

 

[dennis]

Have you checked the impeller and little "filter" that is in the pump? If it is clogged or dirty you could be loosing a lot of water flow.

 

[JanS]

This is a 55 gallon tank.... There's always at least one thing I forget to mention.. :wink:

I do keep the cover on the Whisper all the time. Are there some who don't? :?

Daemonfly, yes I had just done a water change before the photo (I do them once a week). The water level dropped about half way down the reactor. Are there steps you're supposed to take when you do that?
I do see a ton of fine tiny bubbles coming out from the bottom and rising. Last night I had really good pearling - maybe in part because of the water change?

Now today the pH has come down to 7.3 without changing the bubble count.
Would it be common to take almost a week for things to start to balance out? I do have quite a few plants in the tank.
The water flow in the pump seems to be the same as it was from the start, but I'll check the impeller anyway. I know some bits of Riccia have gotten into the little vents, so it's possible.

I hope I'm not asking dumb questions, but I'd rather get it right the first time.

Thanks again for all the useful advice.

 

[bharada]

Just curious but do you see an increase in bubble amount in the reactor as you're increasing your bubble count through the regulator? From what you're saying I would check that you don't have a leak somewhere in your system. Take a spray bottle of soapy water (or Windex/glass cleaner) and spray some on all the connections in your pressurized system. If you see any foaming occur you have CO2 leaking.

I have a 29g tank that I made the mistake of adding a second 1gal DIY bottle to after lights out. The next morning I awoke to find all the fish gasping for air at the surface. Overnight the pH dropped from 7.4 to 6.2. With a KH of 4.5 that equals to >80ppm of CO2. Turns out that the 2nd bottle's mix was extremely reactive (understatment!). The CO2 was being fed directly into the intake of a Magnum 350 filter.

My point is that even after running an airstone in the tank all day the pH was still under 7 when I measured it that evening. So for you to not see dramatic increases in CO2 concentration at the varying bps rates you tried leads me to believe that a leak in your system is bleeding off CO2 before it can enter into your reactor. In my 40gal tank (with pressurized CO2) if I increase the bubble count I can get measurable changes to pH within an hour.

 

[gpodio]

Try removing the sponge at the bottom of the reactor tube. Over the course of the day you get a buildup of insoluble gas in the reactor which does nothing but reduce it's efficiency. By removing the sponge you let out only the tiny bubbles and it seems to work a lot better for me. You may need to adjust the pump output so just the micro bubbles escape the tube. In my case I built the reactor myself so I just used a longer tube with no obstruction. It's worth a try. Other than that, reducing your rate of gas exchange is probably your best bet.

Hope that helps
Giancarlo Podio

 

[JanS]

I unplugged the reactor and the bubble count is the same as it is coming out of the tank. I also checked the connections and they are fine.

Giancarlo, I wondered about removing the sponge, so I'm glad you chimed in. It's certainly worth a shot. I wonder if there's something less restrictive I could use instead....

Right now I'm stuck at the 7.3 - 7.4 range.

 

[paul236313]

i am running the same power reactor i orederd the unit from floridadriftwood i got the controller also and my ph goes from 7.0-6.5 and i am using eheim 2026 i say your hob is taking out the xtra co2 from water movement

 

[JanS]

Just an update on the subject. I removed the sponge and replaced it with a ball of Ehfifix (the stuff that looks like Easter grass). It made all the difference in the world, and I was able to reduce the bubble count and still maintain the C02 level I want. It busts it up into a nice fine mist of bubbles, and yet doesn't want to clog like the sponge can.
I wound up doing the same thing on my Vortex since it works so well.