How come plants grow so fast after water changes?

Re: How come plants grow so fast after water changes?

It's an opportunity. You know the difference between growth and excess gases hanging around? You can tell when a plant is really growing well, vs just having some gas attached to it.

You are not going to like this nor believe me, but it's CO2.
If the nutrients are the same, what else is missing that the water change will add?

Typically good CO2.
In my tap, I had high PO4, that and the CO2 really drove my plants nuts.

If you do large water changes, you also expose the plant leaves to the air, where they can take in large amounts of CO2.
Also, bacteria also get a shot of O2 generally in excess also.
That and the plants O2 release can drive the system hard for a full or two, then buy the 2-3 day it slows down, and by the week's end, things are much slower.

If you do 2x a week 50-60% water changes, you'll see mostly excellent growth.

Means you could stand to add more CO2 if...............and only if you like what you see(all that growth and pearling).

I mean more pearling than an ADA tank.........

That water change allows you to see what the potential max growth is when you have non limiting nutients and CO2.

So that is a very useful and wise thing to observe and use to your advantage when applying steps to improve your aquatic horticulture.

That is an opportunity to achieve that for 7 days a week.
CO2 mist can help.

Think about it and think about the gas exposure to the leaves during a water change.

Regards,
Tom Barr

 

Re: How come plants grow so fast after water changes?

Well, all you have to do is change the additions to higher dosings, EI is useful, you can even bump things up higher than that if you wish.

The amount of accumulation of organic fractions is not a huge effect, not to the extent you see the increased pearling and the dramatic increases in growth...........

So while you might skeptical of the CO2 explaination, it holds more credence than the other possibilities..................

I've also seen and maintained that same growth and pearling etc you see all week and for several weeks without water changes..............

Co2 was the main key.

And given it's role in aquatic plant growth, it makes the most since in terms of increased plant growth, homrones, allelopathy, DOC etc..........none of that fits well.........nor do they produce dramatic impacts on growth, nor are they removed that much by 50% water changes, so there is some there all the time.

Adding inorganic forms of nutrients can help, but if you dose 3x a week, then that is non limiting also.

You really have only a few choices if you think this through.
Try the CO2 mist and then see.

I'll respond more a little while later.

Regards,
Tom Barr

 

Re: How come plants grow so fast after water changes?

Well, the ferts don't do this with my plants, nor ever have, even at very high levels. So that's doubtful.
Tap would not help growth only to a few days later reduce growth.
So no retarding agents, if you want to provide a control for reatrding agents: add some activated carbon, it'll remove any of that.

Did you say well water?
Hahha, there you go, well water is loaded with CO2!!!!!!!!!!!

Well water comes from rain, then goes through trh ground, as it does so, it picks up CO2 from bacteria in the soil, often the ground water is extremely high, you also live where there is significant limestone karst.
Adding CO2 rich water to limestone produces caves by dissolving the CaCO3, as the CO2 degases, it can form stalagmites etc.

The hunch I had was correct it seems.......
Your tap is loaded with CO2.

I can't disagree on the CO2 assumption but only because I don't know. As you said yourself holds more credence it is not a certainty.
I can't see me going any lower here without stressing the fish to much.
I wish more people experimented and checked things instead of doing landscapes. Well that is me.

[/QUOTE]

Well, I do but I also do landscaping.
The key is some balance.

I think you can add more CO2, increase your surface movement(this will prevent fish from getting gassed) and consider the mist method.

I bet you will see what you seek if you do this path.
Do this path first though, then if you give this a real try, I think it'll solve most if not all the issues.

While testing is nice, CO2 is one funny thing when it comes to deciding on how much you have.

Alkalinity has more than bicarb sources and most test methods measure total, not bicarbonate alklinity. Hydroxide ans borate alkalinity can play large roles.

The temp differences also play a role when you pull the well water up from depth and pressure.

More gas is held in solution at higher pressure/depth/colder temps, releasing that into a tank, the levels will go up even if they are not enriched by ground water percolating through soil.

Regards,.
Tom Barr

 

Re: How come plants grow so fast after water changes?

It's not so much that the well water is rock hard, it's that it's loaded with CO2 and dissolved Ca++.

When you see dramatic improvements in growth with water changes, it's generally only a few things: CO2 is too low daily, PO4 is rather low at the end of the week, mid week etc.

Very few things cause such pearling and plant growth, bubbles alone is something different, most folks know when their plants are producing bubbles and growing well, air bubbles dissolve fairly quick also, O2 from the plants keeps on coming.

Regards,
Tom Barr

 

Re: How come plants grow so fast after water changes?

The mist method is nice since it's easy to get a huge amount of CO2 to the plants without worrying about dissolved CO2 so much.

I use to use multiple water changes to rev my tanks up, but I found bumping the CO2 up had the extact same effect.

Regards,
Tom Barr

 

Re: How come plants grow so fast after water changes?

It's nothing complex other than why it works, a thing of rather hot debate.
The fact that it does work, it rather simple to see.

The mist method is simply a concept of delivery of CO2 to the plant.
It gets away from dissolving CO2 into the water as the primary means of delivering Carbon to the plants.

We add gas and then blast these CO2 bubbles directly into the plant beds in our tanks, not waiting for the gas to fully dissolve. Some gas does dissolve though along the way.

The idea is that gas is much faster at transfer across a distance(say the outside of the leaf to the inside) than a liquid. Try breathing liquid sometime.

The flux, the rate of transfer is dependent on this distance, and the medium it's transfering through as well as concentration.

This is the basic Fick's 1st Law of diffusion.

Well, on every single part of Fick's 1st law, the gas wins.

1. Concentration is defintiely higher than 30-100ppm, the gas in pure form is 1,000,000ppm!
Even if it's only 1000ppm, it's still huge.

2. Distance, the gas hits the plant directly and bubbles rise up under the plant where most have their stomata that take in CO2.

3. Coefficent of diffusion, gas has 10000X higher rates than liquids.

So you can do the math easily here.

The method itself is easy and dirt cheap, perhaps the cheapest next to feeding the gas into a filter(Free),.

You simply use a fine limewood or diffuser stone that produces a fine mist.
Place this stone under the outflow of the filter so that the mist gets blasted all over the tank well.

The better the mist travels around the tank, the better.
I use a solenoid and check valve to turn the CO2 off at night.

Limewood stones run about 2$.

You can use a lead plant weight to keep it down or a rock, wedge into the wood etc and use rigid airline tubing also.

If you target 30-35ppm CO2 and have some extra gas hitting the plants, you get much better results, higher O2 levels than you could before and less impact on fish. You should see pearling after 1-2 hours after the lights are on. With high light, maybe even less time.

Anyway, you should certainly see a much higher pearlign rate than with any other method.

You can also see that the closwer you get to the outflows of CO2 reactors of mist type diffusers, the plants grow much better and pearl more.

All you need to do is mix the mist well and blast it into the plant beds now.
30ppm of CO2 does not mean the entire tank is equally rich in CO2. The outflow of a CO2 mister is obviously going to have far more CO2 than on the opposite side of the tank and you can see the difference in virtually any tank.

Mixing and distribution plays a large role.

Simply adding CO2 mist/bubbles right under a plant can show you the differences vs the ppm in the water also.

Regards,
Tom Barr

 

Re: How come plants grow so fast after water changes?

Please be very careful about adding lots of CO2.
Do this incrementally and slowly, watch the fish and plants careful.

Do not be in hurry here or sloppy. :gw :gw
regards,
Tom Barr