# Water changes make fry grow 4X as fast!?



## CichlidsTank

Do regular water changes of the fry tank make them grow ALOT faster?

If it does, how often/how much water should I change in a 10 gallon fry tank?


----------



## cjacob316

yes they tend to grow faster with regular water changes, some say every day, I would do it as often as possible


----------



## Rhinox

I have heard this before, but I don't understand the logic behind it. Can anyone explain why this works?


----------



## cjacob316

nitrate stunts growth i guess is the simple answer, the better the water quality, the faster the fry can grow


----------



## Rhinox

cjacob316 said:


> nitrate stunts growth i guess is the simple answer, the better the water quality, the faster the fry can grow


I can buy that. I also know that there may be hormones or pheromones or whatever that can build up in smaller volumes of water that signal fish to stop growing, which is what leads to fish with stunted growth and the myth that fish only grow to the size of the tank and whatever.

But, are daily water changes necessary? I don't know if I can buy that anything more than weekly changes helps fry grow faster. I have 24 1"+ mbuna in a 30g tank, and they barely produce 5ppm of nitrate per week. I can't imagine a fry tank producing more than that. And, I can't imagine 1ppm or less of nitrate allows the fish to grow faster than if they were in max of 5ppm nitrate by the end of a week.

But maybe there is more to it that I don't understand. Do you have the non-simple answer? I'm curious about this and would really like to know.


----------



## CichlidsTank

Rhinox said:


> Do you have the non-simple answer? I'm curious about this and would really like to know.


 I'm very curious too.

I wish I had 2 fry tanks, so I could experiment with water changes/fry growth


----------



## Number6

water changes decrease pollution and increase dissolved oxygen... stress levels are reduced, end result, growth.

The hormone/pheromone theory is a myth born of growth inhibiting hormones and thinking that they are something given off by fish into the water as opposed to the truth... that these hormones are important survival tools that trade in growth for more important short term needs. Stress results in the fish secreting hormones to help it deal with the stress, and the "side-effect" is growth retardation. People heard of this fact and the tale morphed online.


----------



## Number6

CichlidsTank said:


> I wish I had 2 fry tanks, so I could experiment with water changes/fry growth


quite a few people have already done this including me, so why repeat when you don't have to 8)


----------



## HDrydr

I clean my two 5 gal fry tanks every week and they seem to do fine. I try not to stress them out too much and I'm very careful on the water temp going back in and I only do less than half change each time.. Keeps it looking better and every thing I've read says to do it frequently...but none say how often.... think it depends on size, quantity and how much you feed the little ones...


----------



## CichlidsTank

My maingano just spit 10 fry (her first time holding) going to do 50% water changes every other day in my 10 gallon fry tank and see how fast they grow.


----------



## bossfish

In my experience water changes play an at least equal role in fry growth than do the quality and quantity of food offered. The more you change your water the better. I do almost complete water changes in my fry tanks 2 or 3 times a week as my schedule permits. I use bare bottomed 10 gal tanks and usually take them down to about 1/2 inch of water when doing water changes. It seems like a lot of work and it is but this is the best way that I know of to get fry off to a good start.


----------



## Sheribobbins

I believe that fry do grow faster with a healthier water environment. I would say change water 40-50% every 3 days and that will make a difference in your fry growth. Also I keep my water temp at 84-85 degrees and I feed them twice a day. The second time I feed them its with a really high protein that brings out the red in fish, I breed red fish, so all these things contribute.

I have a friend who had some fry a week before mine and he has done a water change once in the last month and I've done it about 5 times and my fry are larger than his are. We feed the same and water temp the same only difference the water changes. So my experience is yes! Plus the other day on another post I heard people have been researching this with fry since the 70's and say yes as well to water changes being important.


----------



## CichlidsTank

Yeah, my 50% water changes every other day do make the fry grow faster, alot faster! +1 for water changes!


----------



## JMJ240sx

I just read something about that in a magazine the other day. The author did a test using a 20g and a 10g, with IIRC 20 fry in the 20 gal, and 40 some odd fry in the 10g. He did 50% water changes every day in the 20, and 3 50% water changes per day in the 10g, after a few weeks the fry in the 10g were significantly larger than the ones in the 20g. So according to that source the more water changes you do the faster they grow.


----------



## BillD

If you try to grow out a large spawn of angels, you will quickly see why frequent large water changes are important. If the water isn't clean enough they will have poor fin development, and their growth will be stunted.


----------



## SamTHorn

Wow-I had no idea. Thanks for the share. That's good to know.

~ Sam


----------



## CichlidsTank

JMJ240sx said:


> I just read something about that in a magazine the other day


What magazine? What was the article title? I would really like to read it.


----------



## EGYPTIANovic

When is a good time to transfer the eggs from her mouth to a fry tank or a net breeder?
and i know how the male try to shoo the others away everytime they interrupt their little thing but it seems its having hard to time to shoo the pleco( they sometimes get in the way and be annoying lol), should i remove the pleco to a diff tank or it shouldn't affect as much?


----------



## FlyHigh

I've read that another role water changes play in increasing growth rate is that they reduce hormone levels in the water. The article discussed how fish release and can detect hormones/pheromones in the water. An abundance of these hormones in the water will reduce the growth rate while an absence of these hormones will trigger a faster growth rate. Filtration will not remove these hormones however partial water changes do.


----------



## Robinhud

so why wouldn't a constant flow of fresh water be the best solution for growing out fry. set up overflow with sponge and pipe it to a drain.


----------



## DJRansome

I'm not buying that water changes make fry grow 4X as fast. Unless the "before" scenario included high nitrates.

I think the substances fish may or may not secrete into the water was a popular theory for a time, but is not well accepted today.

If you keep your nitrates between 10ppm and 20ppm (which is a good standard IMO) then your fry should grow well. If you keep them under 10ppm they will grow faster, but not 4X faster.

You would have to have constant dechlorinator and constant heater as well so as not to change parameters.


----------



## Robinhud

right I sometimes forget not everyone has well water that is perfect for ac.


----------



## Mr Chromedome

I cannot say definitively whether it works for Malawian Cichlids, but I have seen the results of massive, frequent water changes, and on the species involved, the growth rate was at least 3 times what the average aquarist sees. As for having to dechlorinate, that problem is overcome by heavily aerating the water for 24 hours. James K. Langhammer, former Curator at Belle Isle Aquarium in Detroit, and one of the founders of the ACA, did 70% water changes on all his tanks every three days. He kept plastic barrels of water, aerated to dechlorinate, not chemically dechlorinated. This was before chloramines, so I would imagine that puts a different spin on things, but "aging" water in barrels allows preparation of the water before adding to the tank regardless. It all depends on how dedicated you are to caring for the fish. As for the question of GIS (Growth Inhibiting Secretions), I believe that debate is still open, but even without it, water changes remove all pollutants - not just nitrogenous waste. These days there is a tendency to overemphasize the nitrogen cycle, but these are not the only wastes produced by biological processes. Removing everything that pollutes does make the environment more conducive to growth.


----------



## DJRansome

I am not disagreeing with that. I'm saying on the Malawi side we like to do 50% weekly changes or more if required to keep nitrates under 20ppm. So given we are starting from a different place...I would not expect 4X improvement.

For fry we often suggest 50% every other day.


----------

