How Long To Leave Lights Off After Water Change

[This Old Spouse]

Fresh water from the taps contains a huge amount of disolved co2, doing water changes with lights on is a bad idea as the co2 levels will be fluctuating massively and it will take your plants a long time to adjust to this in balance. This in turn gives algae a massive upperhand. This is the number one cause of algae. Take it from someone who has no algae. I personally would say wait until the end of the day when the lights go off and then do your water change.

 
i believe your theory is flawed....
 
i never have any algae, and i have done water changes with my lights on for 25+ years,
 
my lights are also on about 16 hours a day,
 
i only have to scrape my glass once every 6-8 weeks, and there isnt any algae, just a very light "slime" on the glass

In that case, Mikey, tell me every little thing about your tank(s) and maintenance routines.

 

[SLIM]

If you're running pressurised CO2 the lights on/off debate should mean a lot less.I'd also be more inclined to think it's a drop in CO2 that would be a problem if any too - I know my tap water doesn't taste like Evian sparkling, nor dose a drop checker go lime green in it.....You'd also have to ignore liquid Carbon being a good cure too, as by design it will fluctuate levels (bearing in mind it's algae killing properties would have to continue over and beyond the stress period induced in the plant)On the other hand if your inclined to change alot of your water every day say an hour or two into the light cycle (when the plants are full tilt) and you're running Lime green - I would see that as unstable conditions, once a week though? Unlikely. I'd look towards constant 30ppm, flow, distribution, lighting first.IMO

Fair point however im not injecting at the mo and when I used to do a 30% water change with the lights on my plants pearld like crazy which clearly indicates the presents of co2. Ok it wont change a drop checker but its enough to fluctuate my tanks natural co2 levels.
Fluctuations cause algae, and I did suffer from algae. I started my water changes after lights out as ps3steveo recommend and hey presto, 3 weeks later, no algae

I agree tho in a high tech tank water changes will drop co2, but this is still a fluctuation yes?

 

[Joshwainwright]

Hmm, I might start doing water changes with the lights off then just as a precaution

 

[This Old Spouse]

I started doing W/Cs with the lights off to help with my BBA problem, and with my other changes it's working. I don't actually do the whole process with the lights off (otherwise I wouldn't be able to see what I'm sucking up the syphon) but I switch the lights off when I refill with clean water. I get incredible pearling when I use this method. I'll be sticking with it. 

 

[Zikofski]

hm interesting i may haft to try this, i think my plants are starting to pearl now not sure tho i shall try lights off whilst filling up sorry to hijack this thread but would tempreture have an effect on algae, in other words a temp drop from 26 to 17 to 19c affect algae?

 

[Mikey1]

 

Fresh water from the taps contains a huge amount of disolved co2, doing water changes with lights on is a bad idea as the co2 levels will be fluctuating massively and it will take your plants a long time to adjust to this in balance. This in turn gives algae a massive upperhand. This is the number one cause of algae. Take it from someone who has no algae. I personally would say wait until the end of the day when the lights go off and then do your water change.

 
i believe your theory is flawed....
 
i never have any algae, and i have done water changes with my lights on for 25+ years,
 
my lights are also on about 16 hours a day,
 
i only have to scrape my glass once every 6-8 weeks, and there isnt any algae, just a very light "slime" on the glass

In that case, Mikey, tell me every little thing about your tank(s) and maintenance routines.

 
 
no big secrets really,
 
generally speaking a 30-40% water change once a week, and rinse my filter sponges every two weeks,
 
that varies slightly from tank to tank, most of my tanks are very heavily stocked and 100+ gallons, some people might say overstocked, but i prefer the term heavily stocked

 

[This Old Spouse]

Got photos?

 

[Mikey1]

Got photos?

 
 
yes lots, i will post some in the pic section,
 
my tanks are not all that "pretty", i keep most of them "bare bottom" without any substrate, and very few ornaments, i find the tanks stay cleaner this way, and the water healthier for the fish, this also makes the fish the focus of the tank, and not the decor,
 
i was trying yesterday to get some close up pics of my tinfoil barbs and silver dollars, but they swim so fast is hard to do

 

[SLIM]

hm interesting i may haft to try this, i think my plants are starting to pearl now not sure tho i shall try lights off whilst filling up sorry to hijack this thread but would tempreture have an effect on algae, in other words a temp drop from 26 to 17 to 19c affect algae?

No mate not all

 

[daizeUK]

I have heard another way around this is to leave buckets of water standing overnight as this allows the CO2 to escape.  Then you can change the water without worrying about lights on or off.
 
Obviously only an option if you do water changes with buckets.  It suits me because my tank is small.  Not that I think it makes a lot of difference if the tank lights are on or off anyway, they're so dim!