Plants love it when I do a water change.

[lanstar]

I've noticed that my plants seem to perl more vigorously for about 24 hours every time I do a 20% water change.

It's not phosphate. The tank's at about .4 ppm prior to the partial water change and my tap water has about .2 ppm. It's not nitrate. The tap water has zero nitrates. It's not iron. The tap water has no detectable iron either. I have hard water, about 7 GH and 7 KH. The tank's GH/KH test the same as the tap.

I'm using Duplaplant and Duplaplant 24 fertilizers. What other nutrient could be in short supply that the tap water has a small amount of that the Dupla stuff doesn't seem to have at all? Whatever it is, Flourish doesn't have it either. I've tried it too.

The plants perl all the time when the lights are on, they just do it more for about a day after each partial water change.

Any ideas?

Thanks,

Tim

[GulfCoastAquarian]

The only thing I can possibly think of is CO2. You don't mention any CO2 supplementation for your tank and tap water has higher levels of CO2 due to elevated line pressure. Most city water supplies pressurize water lines going to your house to 30-40psi. Atmospheric pressure is a little less than 15psi so CO2 levels are probably around 2-3 times that of your tank (unless you're supplementing CO2). The quick burst of CO2 is what might be causing your plants to pearl.

This is what causes the little bubbles on the side of your glass when you pour a cup of water from the tap. Pressurized gas is escaping from the water now that it is in normal atmospheric pressure.

[m.lemay]

Holy crap, I was gonna post that exact same thing yesterday after I did my water change.
Gulfcoasts explanation seems plausible but I have pressurized CO2 in my tank and consistently run about 30ppm CO2. If anything, I would think that in my tank the co2 level would actually go down from all the agitation from the water change. Yet my plants bubble like a champagne glass after I do a water change also.

I wonder if the plants are consuming the ammonia from the chloramines present in municipal water supplys. Ammonia is the preferred nitrogen source for plants and I don't use an Ammo-lock type product when doing water changes. Curious phenomenon! Any body else have any ideas and does this happen to people who have well water with no ammonia present?:aah:

[GulfCoastAquarian]

It could still be gases other than CO2 coming out of solution and precipitating on the leaves of the plants. I notice the same thing when I do a water change.

then again, this could be something similar to the aged-reef phenomenon. After a while, even a healthy, robust reef tends to stop growing in captivity. Some theorize that it could be due to a buildup of toxins.
Perhaps certian dissolved minerals reach high levels in our tanks and actually inhibit growth. Water changes temporarily alleviate these high levels and allow pants to suddenly grow quickly and start pearling.

But as M Lemay mentioned, if you're doing a water change in a tank that is being supplemented with CO2, then it is highly unlikely that CO2 levels are higher in the tap water than in the aquarium.

[m.lemay]

I kinda like the dissolved mineral idea. I wonder if anyone has done any research in this area. Now, I gotta know.

I guess its time to start googling:hehe:

[ridns]

I'd say it must be tied in with the trace elements you renew when you do a water change. Some trace elements are in Flourish but not all. I don't know about the others. :hehe:

[SNPiccolo5]

It is probably some micro nutrients being replaced. Or, chlorine is a micro-nutrient of plants, so maybe they are using that? But no fertalizer will provide every single nutrient plants need, but tap water has tons and tons of different types of all sorts of stuff in very small amounts. Also, it could just be that the water being introduced is "cleaner", not by nitrates or anything, but I think it is fair to say the water from the tap is more fresh than the water from the tank.... just a thought.

-Tim

[lanstar]

It's not CO2 with me either, I keep mine at about 45 ppm.

The idea about "toxins" may apply. I've read that plants emit such things to "protect their turf" as it were.

However, I'm only changing 20% of the water at a time. So, in my case, there would be a maximum reduction in the level of these (there's a name for them but I can't remember it) "defensive chemicals" would be 20%.

For the ammonia possibility... I don't treat the tap water at all. The chloramine levels are low enough in my city water that so long as I change a relatively small amount, it doesn't require dechlorination. So if the chloramine is breaking down and producing ammonia, it's not from any additives I'm using.

My first reaction was that there was some mineral or trace element in the tap water.

Now here is something that may or may not be a clue... In the past, I tried to keep the GH/KH closer to 5 rather than at the 7 or so it is out of my tap. In doing so, I have done a 20% water change with 27 gallons of RO water and a small amount of "RO-Vital" to add a bit of trace elements back and STILL noticed the effect, only to a lesser degree.

... Wishing Sherlock Holmes kept planted tanks ...

Tim

[SNPiccolo5]

It is probably a combinationg of the removing of toxins and introducing trace elements. Either way, it is a good thing! Sometimes, we don't always know why something happens, but as long as it is good....

-Tim

[Buck]

This happens to me too..
CO2 seems to be the only thing that makes my plants pearl like that but I do cant understand either why a small amount of tap water into a tank allready saturated with CO2 would matter...
It has to be something else... I doubt its minerals because my tap water is very soft and so is my tank . The levels are equal at all times...
Also this seems to happening to folks from different regions and water parameters... what is the common denominator of all water ?
I have city water here also... maybe an additive ? hmmmm
Now this is gonna drive me nuts...
...make some room Lemay... Im googlin with ya ! :sad:

[anonapersona]

The common parameter is pressure.

Dissolved gasses include oxgen. Plant pearl at oxygen stauration, easier when O is breaking out of solution.

[m.lemay]

Well I kinda agree with anonapersona. I'm not sure she's trying to say the same thing I'm about to say.

Pressurized water contains higher concentrations of dissolved gases. When its put into the fish tank and depressurized the gases are released which explains why, initially there are bubbles on the glass. As the gases dissipate and rise to the surface the tank water is still more saturated with gas than it normally would be before a water change. Higher gas concentrations in the water column means that the oxygen the plants produce won't dissolve in the water as readily since the tank is at or near saturation levels, therefore it just bubbles and rises out of the tank rather than get dissolved into the tank.

What does this all mean? Basically the plants are not producing any more oxygen than they do normally but the gases they do produce are more visible because they are not being dissolved in the water column.

[PhishNeslo]

tap water usually has very little co2, but it has a lot of other disolved gasses. perhaps the pearling you see isnt only the oxygen being produced by the plants, but other gasses collecting on the leaves. sometimes the sides of my tank "pearl" after a water chage.

phil

[PhishNeslo]

sorry. i didnt read to the end of the replies, or i would have seen other people said the same thing i did. when i say tap water has little co2, i mean it has it in no stronger concentration than in the atmosphere. it has more of it than tap water would at atmospheric pressure, but still relatively little. since other gasses exist in such higher proportions in the atmosphere, it seemed like those would be the gasses that would be liberated due to the drop in pressure

phil

[Sven]

I´m thinking it´s the pressure because the water parameters I have are different from yours and the same thing happens to my, the water in my tap is Ph: 8.9 pretty hard and has no added chlorine.