Poop removal

[aaron]

You should still do water changes, even if the tank is densely planted. The organics given off by the decaying poo will indeed fertilize the plants, but the build-up of the physical matter will begin lowering the Ph. Tanks that haven't been cleaned in a long time are very susceptable to Ph swings and drops.

~Aaron

 

[jesper]

Thats why I buffer the water with calcium carbonate!

 

[samuel]

Hey Jesper,
How you do that?
Sam

 

[jesper]

I am just experimenting though, aaron has a lot more experience than me...
Oh, I just add limestone and check the pH and nitrates. We will see what happens, I am still in need of a cheap way of measuring nitrate though.

 

[samuel]

Jesper,
you still have to do water changes even if you neutralize the water. Rxn of the acids in the water with CaCO3 will cuz build up of calcium salt in your water. If water potential in the water exceeds that of the newt's body fluid, it will become dehydrated. I dunno how Calcium salt by itself may affect newts but i think any solutes in high concentration in the water will affect the newts.

Sam

 

[samuel]

Sorry, i meant water potential of water drops below that of newt's body fluid

 

[joel]

I use some bleached coral in the water for my newts. I read somewhere it provides calcium for its inhabitants but only useful in acidic conditions as will turn into insoluble salts that deposit at the bottom in alkaline.

 

[aaron]

I always forget which it is, but the Kh or Gh of the water will be effected by the remaining organics, and the Ph will become unstable.

~Aaron

 

[jesper]

An interesting discussion here...
OK lets go into it more deeply:

Carbondioxide is produced by the plants at night when they act aerobic and consume oxygen. This will make the water acidic.

CO2 + H2O (--) H2CO3(~1%) (--) H+ + HCO3-(~80%) (1)

Daytime they consume Carbondioxide and produce oxygen. This will make the water more basic(reverse of (1))


Carbondioxide in the water is kept at equilibrium by the air content. Opening your window will reduce content of CO2 in the air thus shifting the equilibrium in the water, CO2 will evaporate(reverse of (1)).

Now adding CaCO3:
CaCO3(s)(--) Ca2+ + CO3- (2)

Combining (1) and (2):
CO3- + Ca2+ + HCO3- + H+ (--) Ca(HCO3)2

Now this is my way of producing HCO3- to buffer my solution and at the same time adding Ca2+ which my newts need. Now when HCO3- buffers acidity(then evaporating CO2 whilst producing water, see reverse of (1)) Ca2+ will accumulate until saturation thereby limiting the dissolution of CaCO3(s)(see 2).

Now there's obviously problems with this, please comment. I didn't quite get the previous criticism.

 

[samuel]

Hmmm, you got me lost there...

. Ok, frm what i learn in sch, u'll get a acid buffer only when you have weak acid (which u have) and a strong base (which u don't) cuz, CaCO3 is not a base. Production of water will veer pH towards 7 and not make it basic (more than 7). CaCO3 will not to my knowledge dissolve in water but it'll react with acids to give, salt CO2 and water. The Calcium salt will build up if u keep adding CaCO3 to neutralize acidity and that i feel is unhealthy to the newts. Pls correct me if i'm wrong abt anythingy.

Sam

 

[jesper]

Hi Sam!
Yes I feel that you are wrong.
1.CO32- (carbonate) is a base
2.CaCO3 dissolves in water
3.Calcium will build up to a certain level then CaCO3 will precipitate, lowering the level of Calcium ions ie an equilibrium.

Will write more later

ps. CO3 is a -2 ion I was in a hurry when I wrote eq. (2) above ds.

 

[samuel]

Yeah, after checking with my frens, i was wrong abt 1

. 2 i'm not so sure since the Ksp of CaCO3 is so small,and for 3, u mean that excess Ca2+ will be ppted out? Are u sure that the equilibrium concentration of Ca2+ and the other solutes are not so high that the water becomes too concentrated for newts to live healthily?

Sam

 

[jesper]

Hi Sam!
Checking the Ksp - 0,000130 mol/kg H20
1 mol is about 40+12+16*3 = 100g/mol =Mw

That means that about 1,3 mg will dissolve in 1l of neutral water - that is a pretty low solubility, depending a little bit on what you are used to working with

Point is that it dissolves readily in acidic water, I should have pointed that out sorry.
The whole idea with adding limestone gravel, as I do, is that it doesnt dissolve very good until the water becomes acidic - so me saying it dissolves in water was not very clear...

Well as you know an ion cant precipitate on its own due, thus it precipitates by binding carbonate and forming limestone again. They are actually selling limestone gravel in a lot of aquarium shops.

Well, no it will not hurt the newts. To dissolve enough calcium carbonate to push the equilibrium back to precipitation you would need a lot of acid - even this will not hurt the newts due to osmosis. The newts need calcium so this is pretty good for them I suppose(?).

 

[samuel]

Ok, ic... Well, somehow i still feel it's safer to stick to water changes and that's what i'll do. Even though ur plan may work in theory, it'll still be safer to get feedback from others who have done the same. Dun risk ur precious waltls unneccessarily

 

[jesper]

I agree totally Sam, I just did a 5% change today. The biggest problems have been keeping the nitrate in check, although my plants must eat nitrates for breakfast. I would really like to have denitrification bacteria working on converting nitrate to N2. This will only be done in anaerobic situations though, the little buggers just do it to get oxygen which is readily available in aerobic environments. I know reef aq. utilize this idea using a plenum setup, I have heard that it will not work for freshwater setups but no reasons why, any ideas?

My point is not to totally avoid water changes but to make them rare, especially I want to know why to do water changes every week (if one has a well balanced aq.) like a lot of people do -

 

[elisabeth]

Jesper, I agree with you. Before I changed my whole tank setup, I had a very good balance, and I really only needed to change the water about every 2 weeks, because of buildup, algae, etc.
Now I'm doing a change every 3 days or so because of the new sand setup, high amonia, and a snail that just won't stop pooping!
I figure if you can find a safe way to reduce water changes, everyone will benefit. I know my newts hate seeing the jar that I use to take out water, and adding water kinda makes them nervous. The less I have to touch their tank, the happier they are.
Also, they don't get regular water changes in the wild. They're not as fragile as some may think.

 

[joeri]

You might want to consider this technic. I use it all the time to refresh water and my newts don't seem to be disturbed by it.

Put a bucket lower then your tank and place a tube in between it. Suck a bit at the end (just till the water is over the tanks edge, you'll see water comes out all by itself. You can even move slowly around with the tube to suck dirt from the bottom.
When your ready to refill the tank place your bucket with fresh water higher then your tank and aim your tube on a rock or so to reduce the current to the max.

It's a crazy view if you would catch me filling my tank; a bucket on a chair on the table
But it sure is handy. Just sharing my experience, feel free to do it your way.

Greetz

 

[jesper]

Hey, thats how I managed to swallow turtle-water 15 years ago, there are tubes with built-in "handpumps" nowadays so you wont have to take the risk with the sucking part

 

[elisabeth]

Jesper, I've swallowed newt water. It didn't taste bad or anything, but I was sick as a dog for a few days later!

Joeri, I've done the whole tub thing. I have accidently sucked up a newt when doing that. He's fine now, but he wasn't crazy about the ride. The jar works better for me, but for refilling, I will try putting the bucket higher. I have limited space though, so I'm gonna have to see how it'll all work out.

 

[jesper]

Muhahaha, you sucked up a newt????!!!