Pei Hwa Presbyterian Primary
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JoeeYee:
My DF achieved the above with no problem... the guppies even started reproducing and we ended up with a few tanks of fish. But I've not been successful yet.
Need to experiment but once you strike a balance, your fish/plants oxygen/carbon dioxide requirement will balance out and you have a self sustaining eco-system...
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Hi Mummies & Daddies,
2moro is PTC...judging from our usual coffee talk, our thread will reach 1000 pages tomorrow...likely hor
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How to teach 默写effectively so that ds can remember it? Vomit blood trying to coach him in this area.
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Funx3:
Yes, according to their age order, though I find I didn't really justify dd1's temperament. Haha.E3,
by the Way, Does Your 3 Gals Got Same Dispositions as the THREE LITTLE MISS .... in your Avatar?
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prisnkc:
How to teach 默写effectively so that ds can remember it? Vomit blood trying to coach him in this area.
I used to ask dd to remember in parts if it's a long para. Remember the number of characters in each phrase separated by commas, to the last phrase ending with full-stop, eg 4, 6, 7, 5 so she'll ensure characters are not missed out when she writes them down.
Now she learns on her own by using this method. I'll only check the 'end-product'. It's easier for P3 so far cos she only needs to memorize individual sentences, not one whole para. like P2. -
JoeeYee:
:thankyou:
Oxygen dissolves in stagnant water by the transfer of oxygen across the air-water interface. The amount of oxygen in water depends on the water temperature, salinity, and pressure and is often expressed as a percentage (0% indicating no oxygen). Most fish cannot live below 30% O2 saturation.Jennifer:
Wld someone pls enlighten me how can air enters into the stagnant water in setup A?
I was told I needed an air pump for our fish tank, else the oxygen in the water is not replenish and the fishes will die. Was I tricked by the shopowner?
I am always under the impression that fish will swim near the water surface to gasp for air when there is insufficient oxygen in the water (again told by someone). but knowing how fishes in water take in oxygen via their mouth n passing the water through their gills, how do the fishes then breathe near water surface?
In stagnant water, the upper layer of oxygen-rich water tends to stay at the surface, resulting in lower oxygen levels throughout the water column. If you put in a pump, it will create turbulence and the oxygen-rich water at the surface will be replaces by water containing less oxygen from the bottom of the tank. More oxygen exchange across the air-wafer interface will take place and eventually, you will have a tank of water that is overall richer in oxygen.
That's why your fish will swim towards the surface to \"breathe\" when they have insufficient oxygen at the lower part of the tank. But instead of buying pump, you can get more aquatic plants. Need to experiment but once you strike a balance, your fish/plants oxygen/carbon dioxide requirement will balance out and you have a self sustaining eco-system... -
prisnkc:
How to teach 默写effectively so that ds can remember it? Vomit blood trying to coach him in this area.
It depends on what type of learner your child is. Some children can sit down to memorise, some hv to move their body, some must see pictures.
My elder boy belongs to the \"must see pictures\" while the P4 boy is the \"hv to move his body\". -
Jennifer:
:thankyou:[/quote]Well-explained, JoeeYee. :celebrate:
Oxygen dissolves in stagnant water by the transfer of oxygen across the air-water interface. The amount of oxygen in water depends on the water temperature, salinity, and pressure and is often expressed as a percentage (0% indicating no oxygen). Most fish cannot live below 30% O2 saturation.JoeeYee:
[quote=\"Jennifer\"]Wld someone pls enlighten me how can air enters into the stagnant water in setup A?
I was told I needed an air pump for our fish tank, else the oxygen in the water is not replenish and the fishes will die. Was I tricked by the shopowner?
I am always under the impression that fish will swim near the water surface to gasp for air when there is insufficient oxygen in the water (again told by someone). but knowing how fishes in water take in oxygen via their mouth n passing the water through their gills, how do the fishes then breathe near water surface?
In stagnant water, the upper layer of oxygen-rich water tends to stay at the surface, resulting in lower oxygen levels throughout the water column. If you put in a pump, it will create turbulence and the oxygen-rich water at the surface will be replaces by water containing less oxygen from the bottom of the tank. More oxygen exchange across the air-wafer interface will take place and eventually, you will have a tank of water that is overall richer in oxygen.
That's why your fish will swim towards the surface to \"breathe\" when they have insufficient oxygen at the lower part of the tank. But instead of buying pump, you can get more aquatic plants. Need to experiment but once you strike a balance, your fish/plants oxygen/carbon dioxide requirement will balance out and you have a self sustaining eco-system... -
E3:
Well-explained, JoeeYee. :celebrate:Jennifer:
:thankyou:
... suitable for adults but I dont think my dd can understand it yet.. :roll:...
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JoeeYee:
Well-explained, JoeeYee. :celebrate:E3:
[quote=\"Jennifer\"]
:thankyou: ... suitable for adults but I dont think my dd can understand it yet.. :roll:...[/quote] :thankyou: JoeeYee!
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