CO2 and water filter

[JT]

This question has been bugging me since starting of my planted tanks journey. Does anyone knows if CO2 content/amount is affected by water aeration/filter. ie. I normally shut off my filter in the day when my CO2 is on. However I do see some of the shop have both the CO2 and water filter on together. My Q, does the filter(water movement in the water) affects the CO2 content? Thanks

[bclee]

You should not switch off the filter. You will cause the nitrifying bacteria in the filter to be starved of O2 and die off.

What type of filter do you have? Unless you have a wet-dry type of filter, you should not experience too much CO2 loss, if any at all, caused by the filter.

Water movement itself has no effect on the CO2 loss. It is the agitation at the interface between the water and atmosphere that accelarate the CO2 loss to the atmosphere.

In wet-dry system, e.g. sump filter, overhead filter, the filter provide lots of interface of contact between the atmosphere and water to provide aeration to the water for the bacteria. Gas exchange takes place at the interface, CO2 out of the water and O2 into the water.

In internal filters or canister filters, there is no interface. So no gas exchange take place in the filter. The filter rely on water intake to bring in O2 rich water for the bacteria. That's why one should not turn off the filter for prolong period.

BC

[juggler]

[quote:d00aa8d516="JT"]Does anyone knows if CO2 content/amount is affected by water aeration/filter.[/quote:d00aa8d516]

If you water aeration is done by air pump, then better turn it off all the time as it will drive out the CO2 in the water.
If using pumps that circulate water only, keep it running.

[moss_fanatic]

How about using a hang-on filter and a fan system?
will it affect the co2 too?

[vinz]

Moss-fanatic, welcome to AQ. Actually, if you read BCLee's reply again, you will find the answer in the 3rd paragraph.

In AQ, we try not to spoonfeed. Else the forums will be cluttered with simple questions that could have been avoided if the poster had bothered to read and try to understand first.

If you don't understand bclee's reply, feel free to ask.

[JT]

Thanks all the experts for the answers. It is most enlightening...K will tune the timer of my filter to 20hrs instead of the 12 hrs cycle.

[budak]

Why 20 hours? If you have a reputable brand of filter, it should run 24/7. Eheims, and the better Taiwan brands, easily run nonstop for years (except for cleaning every few months).

[lorba]

Stopping the filter for a few hours may have negative impact on the beneficial bacteria inside.

[wf7850]

[quote:18cee3e5b0="lorba"]Stopping the filter for a few hours may have negative impact on the beneficial bacteria inside.[/quote:18cee3e5b0]


my block will be having power shutdown this Fri from 0830 to 1800....

my poor bacteria.......

[budak]

hi wf,
i sometimes get that too. but if your tank is in fair shape, it should be able to take it. What you can do is maybe just before the scheduled shutdown, take the filter out and open the top, and then put it under a slow-flowing tap in a pail in your bathroom. After lights are on again, plug back, and do a water change. But it's also possible (if you don't want to do that) that you can just do a large water change after the lights are back, and dose in new BB in the tank to rejuvenate the filter media.... I have done that.

[wf7850]

Hi Budak

Thanks very much for the advice. I will most prob take yr second advice and do the large water change after coming back from work Fri evening.... will update u here on the outcome....

Thks...!!

[RonWill]

[quote:bb956313="JT"]It is most enlightening...K will tune the timer of my filter to 20hrs instead of the 12 hrs cycle. [/quote:bb956313]
JT, it's obvious you're not sufficiently enlightened. The gurus said to leave filter running... 24/7 period! Not 12, not 20 hours.

The CO2 loss, if any, is really negligible and doesn't warrant the expense of a timer.

[vinz]

[quote:5dd7e25fb1="budak"]...

What you can do is maybe just before the scheduled shutdown, take the filter out and open the top, and then put it under a slow-flowing tap in a pail in your bathroom.

...[/quote:5dd7e25fb1]

Wouldn't that be the same as washing the flter media with tap water? Which we do not do because the chlorine might kill the bacteria?

[budak]

i have been dumping fresh tap water into my tank and filter all this while..... never touched anti-chlorine for years..... of course his mileage may vary..

[vinz]

Well, I've had a few problems presumably solved with anti-chlorine, so I rather play safe and not use tap water on biological media.

Anyway, I get water straight from the mains. Those above the 4th floor of a HDB flat are most likely getting it from the roof sump. This could make a diff in the levels of chlorine if the sump water has stood for a while.

[JT]

Yup agreed...but i have my concerns...thus it was 20hr not 24hrs. Personally I have experiment with it and I know for sure what is what. Back in my office, my filter run on a 12hrs cycle - alternate with lights and CO2 in the day. The effect - beautiful bubbling effect from the plants. with the 24hr filter running, the tank still goes well, but the bubbling effects does not occur. (my filter is in the tank itself - self design at the back of the tank, water runs from back to front.)
However, my concern was the 4ft tank at my house. It has yet to stable and I'm trying to adjust each components to stablise the condition of my tank. The fishes and plants are not particular healthy at the moment, thus the original question.

[budak]

Could you share exactly what are your concerns about not running the filter 24/7? I find it rather strange.... the shut-downs could be what's screwing up your system (the 4 ft tank). As some have said here, bubbling is NOT an indication of plant health or photosynthesis - it only menas that there is so much oxygen saturated in the water that the extra oxygen produced by the plants becomes visible as bubbles.

[JT]

Thanks...funny it may seems. I'm still trying to figure out as well. When I run the filter 24hrs, my plants starts to die/colour becoming pale and witering...yet if I kept the filter at 12hrs type, my fishes starts to die off...the fishes dont die in a mass, its just die off 1 or 2 per day... ??
Thus I reckong trying to regulate the filter timing to suit both plants and fish, thus the 20hrs and adjusting...to balance..

[budak]

Most probably, when you stop your filter, the resulting ammonia spike (as the bacteria die) kills the fish. Whereas, while the filter runs, bacteria can convert ammonia into nitrite, but may not yet have time to produce enough nitrate for the plants.... or it could be simply be that your plants were still not acclimatised to your tank.... with a CO2 injected setup, No3 addition is often necessary to keep the plants well fed. But in any case, I am pretty sure running the filter non-stop should not have any ill impact on your plants (what species do you have?), if you have your other factors sorted out.

[JT]

Agreed. That y i plan to run 20hrs...The break is not a long 4 hrs but spread over the day. I suspected so as well...I add liquid nitrogen into the tank as well.I just waiting for it to stablise over few weeks....(Maybe when I add the liquid nitrogen, the fishes charges up to 'eat' it may cause some poisoning)...hahaha.
Well, thus far, since the last 3 days...everything seems quite ok. only 1 prawn died. I rear tetras(neon tetras and rasbora espei). my ottos not doing well as well. since start, 7 out of 10 has die. 2 sae and mollies doing very well...