Getting fry to grow quickly

[GTR73]

I have P.saulosi fry in a standard 2ft, change 50% the water with about half cup of rock salt once a week, feed them HBH Veggie flake twice a day, and they seem to grow pretty damn slowly. Healthy, but grow too slowly for my liking - take about 3mths to get to 3cm.  

What methods do people use to get their fry to grow quickly.

cheers. 8)

[coalgrunter]

You could try using a bigger tank for grow out. Larger the better

I think the size of the tank has alot to do with it, and have really good filtration, if you have an overkill of filtration, aslong as the fry are eating the food, just keep feeding them, but make it consistant so the filter can handle it.

You dont want food on the bottom of the tank. I think half a cup of rock salt in a 2 foot tank is alot aswell. How many fry do you have in this tank?

[GTR73]

Yeah just went to edit my post (quick on the responses!) - I actually use 1/4 cup for a 50% water change or about 1 teapspoon of rock salt to 18 litres (or one bucket). My 2ft is about 54L, so for a 50% water change I use approx 2 teaspoons (or about quarter a cup). Despite my intricate measurements I mentioned, I try to keep it all pretty relaxed and don't get too stressed out with exact quantities (One teaspoon per bucket. Simple).

For filtration I have a 576L/hr internal canister (large Hagen canister) that uses scourer type filter mat and bioballs up the guts of it. And a spray bar offthat so the little fry aren't swimming the butts off all day and to get the food easily.

But you're right about the tank size - maybe I should get a 3ft?

I've got about 30 fry in there ATM, ranging from 1cm to 3cm.

[bryce2003]

Try smaller water changes more frequently. Something like 10-15% water changes every 2-3 days. Should help. You can also try putting the temp. up to a canstant 28*C, from what I've been told it makes them grow quicker as they eat more due to a faster metabolism or something. Never done it so can't confirm. Hope this helps.
Cheers,
Bryce.

[Thanes]

Try doing 10% at least once a day.If not twice a day.
Brian.

[dammwoman]

As everone said a bigger tank and more water changes will speed them up but if you have a strong filter output this will slow them down as well as they use energy to swim against it instead of putting that energy into growing.  Spray bar as someone mentioned is a good idea. I try to feed fry 4 times a day and include live food in that then bottom syphon at least every 2 days
Cheers Linda

[GTR73]

I'm actually the one that mentioned spray bar, it's on the fry tank filter for that reason - so that they don't burn too much energy.

Thanks for the responses everyone. I think the only feasible idea at this stage is to try increasing water changes and see what happens.

Cheers
Brad

[sealord1au]

you could try NLS growth formular as well

my frontosa fry goes from free swim to 4cm in 8 to 9 weeks

[DeagonTheo]

You wont get them to grow much faster than that anyway, maybe get a bit closer to 3.5 to 4cm but thats about it.
Try a bigger tank, more protein and feed more often and keep up the water changes, but unfortunately making your  1st $1,000,000 out of fish doesn't happen overnight.
Theo

[GTR73]

Yeah just wanted to gauge if my growth rates were good/bad/indifferent, and that I was reasonably on the right track regards looking after my fry.
(plus this is good discussion for people just starting out breeding)

cheers for the help.  :)

[gasnitro]

you say you add rock salt! are you adding anything else?

[GTR73]

Actually it's more like 1 teaspoon-sized cup of rock salt (sodium chloride) per 18L bucket - I actually thought I edited the "half-cup" bit from my original post. :?
I have Epsom salts (magnesium sulfate) for GH and Baking soda (sodium bicarbonate) for KH on hand, but have never worried about hardness or PH. Brisbane water is pretty well right straight from the tap.
I add rock salt as I think this is essential for Africans - both sodium and chloride is found in Lake Malawi - and my fish are always happy with it, they breed and display good colour. So I'll keep adding it and not too worried about the other elements.
So yeah, I use a 1 teaspoon per 18L equation, and it's Sodium Chloride as Rock Salt, not table salt.
If I need to add the other elements I use the same equation.
Not sure if people would agree with this method but my fry seem to be growing at normal rate apparently, my fish are happy and looking good, so works for me.  8)