A.M. pH spikes

scottracy

scottracy

Got Roy?
Jan 3, 2004
333
0
0
56
Texas
Visit site
I have been observing a pattern with my fish being at or near the top of my 55g planted tank early in the a.m. prior to lights on. After an hour or so with lights on they seemingly resume what I would call normal behavior. They never appear to be particularly stressed.

This morning I checked the pH and it was 6.6-6.8. I give this range because the color indicator is difficult to distinguish. Normal pH is 7.0 with lights on which gives me a CO2 of 30 ppm.

I use pressurized CO2 injection with a PlantGuild Power Reactor. I do not use a solenoid and the CO2 stays on 24 hours/day. Can these night spikes be controlled with a simple electrical timer used in conjunction with my lights? Obviously the CO2 is still injected into the tank but with less suspension of gas into the water.

Scott
 
I'm guessing that since plants do not use CO2 at night and in fact actually produce it along with the fish, you have too much in there at night. Once the lights go on the plants start to utilize the CO2 and thats why your fish look better after an hour or so.
 
Karnaaj is correct and a timer is usually advised for pressurized CO2 systems. Lights off, CO2 off. If it was a simple DIY injection system it usually turns out to be a non-issue simply because the DIY CO2 reactors are not nearly as efficient of course, as the pressurized CO2 systems. You were correct in your post Scott, a timer is the way to go.
 
Leaving the CO2 on 24 hrs a day will ineed cause a ph spike overnight. However, I don't think a ~0.3 change over about an 8 hour period would be anything to worry about. It sounds more like a lack of oxygen. Do you have enough water circulation in the tank? If you're using CO2, you don't want to have too much current at the surface, but you can have a nice amount of current mixing the rest of the tank water to prevent dead spots.
 
Just tune the bubble rate down to achieve an AM pH of 7.0 and observe the fishes reaction. A simple enough experiment with pressurized.
No need, IMO to time off the CO2 at lights out unless you're trying to save the CO2.
This can cause more issues with rising pH in the long term, creating more stress than a small, over night spike when left on.
The object is to achieve consistency.
I have found that, in an established, healthy tank there is a reduced need for pushing the CO2 ppm up to the edge. I'm keeping my ppm in the 20 - 25ppm range in my stabilized tanks with little or now reduction of growth.

Len
 
I will tweak the CO2 as suggested by Len and measure the pH and fish behavior.

In the rescent past I felt that my current was too strong. My angels and plants seemed to get blown around too much. I switched CO2 reactors from the AC 402 powerhead to the PlantGuild Power Reactor and changed the reactor location. I thought this to be a great improvement. I probably should up the current or distibute it better. I think I wil reposition my intake and output tubes differently to help eliminate dead spots while balancing the strength of current to the preference of the inhabitants.

Scott
 
Last edited:
I've seen your tank and your fish are not oxygen deprived. Water movement is good to have, but your fish are not lacking oxygen.
They could be stressed due to high carbonic acid levels. Hence the test to see if improvement is seen.
Trying to get a handle on many of the parameters with some of the junky test kits, and ridiculous color charts out there is a joke, IMO>
Let us know how they're doing.

Len
 
I'm with Len, if your plants are growing well and pearling pretty much all day, the fish certainly aren't O2 deprived. I'm running DIY, so I have little control over CO2, but I think (again with the test kit colours!) that I've actually had CO2 concentrations rise up into the 50's or even 60's. While I was panicking and opening pop bottle caps at night and such, the fish never showed any sign that they were stressed. Their behaviour was identical to when my CO2 levels were 'proper'. No that I'm advocating pushing CO2 up, I think that it's more the case that I was lucky than the norm, I'm just saying that I don't think that a timer is necessary and I'm not sold on CO2 levels rising uncontrollably overnight. What types of fish are they? I've noticed that my new additions (gertrudes rainbows) like to "sleep" near the surface while others hang out lower.
 
I dialed down the bubble rate last night. The pH this morning at 6 a.m. was 7.0. All the fish were fine and not at the top of the tank. This was a simple fix! Thanks for all the advice.

Scott
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom