Water Change Frequency with Fry

[davidjp1982]

Ok so I've got 10 fry at the 2 week stage of my first Cacatuoides spawn - I've moved the male to a 10 gallon tank so it's just the female and fry in the main 15 gallon. I was doing a 25% water change every day but as I used some of the water in setting up the 10 gallon they had pretty much a 50% water change yesterday. Due to the large water change I was going to miss today but wanted to check I'm not going overboard for no reason on the frequency of the changes. Could I step back to say 25% twice a week? This is the amount I have always changed however. Also feeding 1ml pippette of fresh BBS 4 times daily if that makes any difference to water changes? Thanks in advance.

 

[davidjp1982]

Also I have noticed occasionally 1 fry going crazy and flicking against the sand / jerking around for short periods. I just noticed it again and hope it is just the one fish. Is this anything to be concerned about? It's one of the larger fry so wouldn't think it is one of the weaker ones?

 

[Psycho74]

The 50% change was way to high IMO. I've got around 40 fry at the moment and try to unsettle the conditions as little as possible. 25% water change per WEEK is sufficient and keep the flow rates low as they prefer calm water. Did you pick up some almond leaves? And I assume your conditioning your water? I would suggest it would be the water change that causes the fish to scratch against the tank.


Cheers,
Shane

 

[wethumbs]

My cacatuoides spawns are usually around 100 with the most over 350. I usually don't disturb the fry with water change for the 1st week. Thereafter, a 10% daily water change to help clean off the uneaten food that has been building up. By the third week, it is up to 30%. Before I know it, they are on a 80% daily water change cycle. You just make sure the water is properly treated with dechlorinator and temperature, pH are a match (within reason). I gauge the water change % base on the fry size and step up from 10% to 30% to 50% to 80%. I don't use any almond leaf, or alder cone, or any of the 'feel-good' additives to the water, just plenty of good clean water.

If you are doing the bucket brigade technique like most people are, then doing all these water changes can be a hassle for 10 fry.

 

[davidjp1982]

I wasn't at home for the first 4 days of the spawn this is just a guess as I saw a change in behaviour of the female before I left for a few days so I am guessing I possibly lost a few fry to the male and or filter when I was away! Thanks for the advice on water changes will adjust to suit

 

[danbb]

I got fry since yesterday and I want to know how much water I need to change. It's ok to keep constant changing rate or I must increase weekly? I must change every day I guess, or just weekly?
Thank you,
Dan

 

[danbb]

One more thing: half of the aquarium where fry and mother are swimming (until now) is opposite side from the entrance of the outer filter. Should I cover the entrance with something so the fry don't get suck in, or leave it as it is? Water flow is reduced to more than half.
Thanks,
Dan

 

[gerald]

In fry grow-out tanks I use lots of fast-growing plants like Limnobium, Najas, Salvinia, Elodea, or Ceratophylllum that is easy to remove. The plants absorb the nitrogen wastes (ammonia, nitrite, nitrate) and I remove the excess plants as they grow. Following that strategy I don't need to change water as much (maybe 25% per week), and the water quality remains excellent.

 

[danbb]

I want to keep the fry with their parents in the main tank, here I got (and want to keep) only surface plants: pistia stratiotes, duckweed and eichhornia crassipes. I think I will change 10-15 % every day.
What to do with entrance of the filter: leave it or cover it?

 

[Mike Wise]

Cover the filter tube with a piece of filter foam. From experience, seeing a batch of fry stuck in a filter is not pretty!

 

[danbb]

Ok Mike, I will. Thanks.

 

[danbb]

After how long it's safe for the fry to remove the sponge?

 

[Mike Wise]

When the fry are too large to be pull into the tube's strainer.

 

[danbb]

Even if the flow is low (reduced more than half) and the fry are about 2 weeks old? I only got about 12 fry left with theire parents, rest of the fry are into a tank just for them. I said it's better to let few fry with theire mother.

 

[gerald]

Why not just leave the sponge on permanently? It makes a good pre-filter, so you wont have to clean out the filter container as often. And if any fish spawn that you don't notice, it will help protect them too. I use mostly internal air-powered filters, but the few external motor-driven filters I use all have Poret foam blocks on their intake.

 

[danbb]

I noticed that filtering is not so good even if you change 10% every day and pull out the dirt from the bottom. Maybe I'll try to use a sponge with holes a little larger, this one does not allow only water to pass through it.