How does water affect growth

[henpecked]

I have my first successful fry on the 5th try:D The father is a good 8", so I know the fry have the genes to achieve growth.
Right now they are in a 10G (there are only 4) at 3 weeks old.

I have always read that the water in a fry tank should be changed daily. Isn't that a bit of overkill ? How much do WCs really affect growth? I would think that the beneficial properties of new water and 7 day old water would be very similar as long as bio-mass is reasonable and filtration is heavy.

I'm here to learn, so please give me your thoughts on this topic.:)

[Moon]

It's the build up of nitrates that affects growth. You may have very good bio filtration and that itself creates the nitrates. The only economical way to control nitrate build up is by frequent WC.

[JaredP]

There is also a school of thought that discus excrete a hormone that inhibits growth. The thought process is in the wild, if they are in a area with very low water flow, this will prevent other fish from growing. This stops there being any supersized fish that would consume more food.

Again, water changes fixes that problem.



A quick google source for information

"1. Changing water

This first point I have experience it myself by accident and I find this very true. Let me tell you what I did.

I had a new batch of 2 inch Discus and I placed them in a quarantine tank. 50% of the water was changed everyday and YES, they grew bigger and faster than I had ever seen. They were 3 inch in size in one months time. My baby Angels in the other tank was growing even slower than the Discus. To make sure, I went back to the aquarium to check out the other Discus in the tank where I caught mine. Indeed they were much smaller than my Discus.

There may be a few reasons to why this promotes a growth spurt. None of them are 100% correct or neither am I sure of it.

* A world renown Discus breeder Jack Wattley, believes that all Discus secrete a growth suppressing hormone that builds up and slows the growth rate of other Discus. There are always a few Discus in a tank that have a tremendous size advantage. Keeping the smallest Discus with their siblings results in continued slow growth. However, moving these smaller ones into their own tank generally causes a large growth spurt.

* Nitrates are thought to be an impedance of Discus growth. That is why many Discus owners like to have planted tanks to get rid off nitrates that plants readily absorb.
""


Source: http://www.zestweb.com/articles/growth/growth.html

[henpecked]

Thank you very much for such detailed info. That is exactly what I was looking for. I will make the commitment to it. I can easily do 30% every day, does that sound about right?

[Eddie]

Ammonia retards growth. Small fry need to be fed often and this can cause fouled water which leads to ammonia build up and bacterial outbreaks.

Eddie

[henpecked]

Thanks Eddie,

I see you all over this forum and I really value your advice.:D

[JaredP]

Thank you very much for such detailed info. That is exactly what I was looking for. I will make the commitment to it. I can easily do 30% every day, does that sound about right?

If you have them in a 10 gallon, you need to do 100% a day, i know a few breeders do 2 100% changes a day. Water quality is the key to healthy growth.

[DerekFF]

Its only a 10gal, but theres only 4 fish so there shouldnt be a huge bio contam as fast as most people here would probly expect. But at the same time it is only 10 gals so its a breeze to change the water.

[JaredP]

Its only a 10gal, but theres only 4 fish so there shouldnt be a huge bio contam as fast as most people here would probly expect. But at the same time it is only 10 gals so its a breeze to change the water.

Yea, missed the spot where she said just 4 of them, I was wondering how a full set of fry fit in a 10 gallon..

But yea, it's easy to change out so it's worth changing as much as possible.

[Jhhnn]

I'm of the opinion that it's basically impossible to overfeed growing discus, but that it's easy to overfeed the the tank they live in. No amount of conventional filtration will change that, but large and frequent water changes will overcome it...

Ther's a point of diminishing returns, I'm sure, but finding it entails flirting with disaster. Properly executed, changing more water than necessary won't harm the fish in the slightest.