How do you do a "cool water change" to stimulate corys and plecos when you've got this?!?

[bekateen]

Here's the "cold water" straight out of my tap. Dang it, global warming!

[backstreetgambler]

lol

[MChambers]

Ice cubes?

[bekateen]

Ice cubes?

That's about it for now. Recently, I've started doing something similar: For one of my tanks, I'm filling two 18-oz bottles with water everyday, freezing them overnight, then adding them to the tank the next morning. This is a 20 gal tank. Sadly, these two frozen bottles thaw within a few hours and the temperature doesn't drop more than 2-3F; by afternoon, the tank is back to normal. I don't know if the small change will have any effect. I'm not sure how it can, since I usually do dramatic water temp changes (8F, sometimes greater), but I might as well give it a try. Fortunately, these are Hypans and Panaqolus, so they don't mind the high temps from day to day.

Cheers, Eric

[Bas Pels]

Ice cubes won't do much. Firstlyk, addin a few kilos of icecubes (-25 C) in a hundred liter tank (+25 C) will lower the temp only a few hundreds of a degree. Which is nothing

Adding more will risk the fishes freezing to the cubes, killing or harming them

I would think of something like an aircondioner, preventing the need for a cooling waterchange

[bekateen]

Ice cubes won't do much. Firstlyk, addin a few kilos of icecubes (-25 C) in a hundred liter tank (+25 C) will lower the temp only a few hundreds of a degree. Which is nothing

Adding more will risk the fishes freezing to the cubes, killing or harming them

Overall, all true, except in my case the plastic containers can't freeze the fish (the water inside the bottle melts first around the bottle's wall, creating a thawed boundary layer; inside is a nucleus of ice, positioned away from contact with the fish).

As to temperature change, yes it's negligible. For those who are wondering why, let me show you. Academic integrity warning: I'm going to perform some really sloppy chemistry here, so forgive me:

I have two 18-ounce bottles of water, each with about 17 ounces of water frozen, at about -18C. (First sloppy generalization: The frozen water is at -18C. In reality it is not; I don't know the temperature of my freezer, but a typical freezer is set at -18C)

2bottles x 17oz water/bottle x 30ml/oz = 1,020ml water = 1,020g water (Second sloppy generalization: Never mind that water density changes with temperature, so 1,020g of water won't have the same volume at -18C and at 27C, and by inference, 1,020 ml of water won't have the same mass at -18C and at 27C)

The specific heat of ice is 0.49cal/g/degK and 1degK=1degC.

Therefore, to raise the temperature of the ice water from -18C to 0C, this will absorb:

1,020g x 18C x 0.49cal/g/degC = 8,996cal heat

The heat of fusion of water at 0C =79.7cal/g, therefore to convert all this water from ice to liquid would absorb:

1,020g x 79.7cal/g = 81,294cal heat

Now I have 1,020g of liquid water at 0C in these two bottles. To equilibrate this with pre-existing aquarium temperature (27C):

The specific heat of water is 1cal/g/degC. (Another sloppy generalization, but not likely my third: A specific heat of 1cal/g/degC only applies to water starting at a particular temperature and pressure, so it won't be universally true from 0C to 27C)

Therefore, to raise the temperature of the liquid water from 0C to 27C, will absorb:

1,020g x 27C x 1cal/g/degC = 27,540cal heat

In total, the bottles will absorb:

8,996cal + 81,284cal + 27,540cal = 117,820cal

Now, this is a 20gal aquarium. Assuming approximately 4 gallons of water volume are displaced by sand, rocks, caves, and wood (and assuming there is a small air space at the top of the tank because it's not entirely full), that means there are 16 gallons of water in the tank, which is

16gal x 128oz/gal x 30ml/oz = 61,440ml water

IF all of the heat needed to melt and warm the ice could be transferred from the aquarium to the bottles without any additional heat entering the tank from the surrounding house, then this means I would extract

117,820cal / 61,440ml = 1.9cal/ml on average,

resulting in a maximal cooling effect of 1.9C. (Another sloppy generalization, and this is perhaps my worst yet: I've only calculated the effects of the ice on the water. But of course, for this to work the ice must also cool off all the objects (rock, sand, wood) inside the water also, and I omitted them from my calculation. Although I didn't look up the specific heat of sand, rock, or wood, I doubt they are 1cal/g/degC, but they will be significant. Adding the rock, sand and wood into my calculation would bring down the maximum cooling effect a LOT more.)

However, of course the ice doesn't melt and warm all at once, and there are simultaneous infusions of heat from the surrounding house environment to replace the heat lost in the aquarium water, so even this small temperature drop will not be realized.

BUT... (and there's always a but)... the other truth is that I don't have instant and uniform mixing of the cooled water with the warmer tank water. The floating frozen bottles do create locally cooled areas of water, and this flows on currents until the thermal gradients are homogenized. I.e., cool water at the aquarium surface flows across the tank and down to deeper levels as notable currents. That's why I reported above (perhaps deceptively but without guile) temperature drops of 2-3C in the tank: My aquarium thermometer is in the flow path of the chilled water, so it registers a temporary drop of 2-3C. But of course this is not representative of the tank as a whole. My intention in adding the ice blocks is not to actually cool the tank water down as a whole for the entire day; after all, I mentioned previously that the ice melts within a couple of hours and by then the effect is completely neutralized. But rather, I'm hoping (and this is possibly wishful thinking) that the "wafts" or currents of cooler water will catch the attention of the fishes and still stimulate them.

More than likely, nothing will come of this trial, which I'll keep up for about a week while we're having this awesome 38C-43C heat wave outside. None of the plecos in this particular tank have EVER spawned for me in the past. But if they do, you know I'll be celebrating. The male mustard spot has become very hairy just in the last 3 weeks. And for about a month now, all of my mustard spots have been aggressively stealing meaty foods from the hypans (boiled clam and live black worms), in addition to their sweet potato, wood, and zucchini. Maybe the combination of extreme heat and wisps of cool water will get them going.

I can only hope.

Cheers, Eric

P.S., I don't normally perform this kind of calculation, so if anybody finds a mistake in my math or assumptions, please let me know.

P.P.S.,

I would think of something like an aircondioner, preventing the need for a cooling waterchange

The cost of air conditioning a house the size of mine to a temperature so cold as to make my aquariums "cool" when the outside temperature is 38C-43C would be excessively expensive, so that is not a viable option for me. Also, that wouldn't change the temperature of the water coming out of my tap. However a water chiller would probably be a good solution for temporary use.

[apistomaster]

The benefits of simulating seasonal water cooling are likely overestimated by hobbyist breeders. The most influential factors with regard to water are usually the water change volume, frequency and chemistry.
Feeding of live foods is extremely helpful when it comes to obtaining breeding success.

[bekateen]

Perhaps so, given that unless your house is cool and the aquarium is unheated, water temp is restored within hours of a routine change (even if a big one). To my knowledge, nobody has published on how extreme and how long (duration) the temp drop needs to be in any species to reliably activate the hypothalamus-pituitary-gonadal axis or to release a courtship/spawning behavior program. That would be something to read.

My water changes vary in amount, but when trying to trigger spawning, I usually go for 75-90% with pure cold tap water. That, with a couple doses of live black worms on the days before and day of, will send most of my corys into spawning frenzy within the next 24 hr. Clown plecos don't seem to NEED the water change, but they do often breed right after a big WC also.

Maybe the cool temp is overrated, but that doesn't by inference mean it is inconsequential either.

Cheers, Eric

[Jools]

Depends on the fishes, some are triggered some are not by cool and clean water, some it's just clean. Engineering to run a hose through a fridge is a fun but often useless project as the tank ends up too hot when water from the tap/faucet is this warm.

Advantage of living in Scotland #231 - not an issue I have.

Jools

[Shane]

The simplest solution... wait until late fall/winter. Other advantages are the shorter diurnal cycle and softer tap water which also help mimic wet season conditions. Plus it will be crummy outside so you will be in the fishroom more often.
Just my $.02
-Shane

[bekateen]

The simplest solution... wait until late fall/winter. Other advantages are the shorter diurnal cycle and softer tap water which also help mimic wet season conditions. Plus it will be crummy outside so you will be in the fishroom more often.
Just my $.02

That's a good $.02.

Fortunately for me, this was only a temporary problem: The warm water coming out of the "cold" faucet was associated with a heat wave in my area (102-109F for the last 8 days). Temps are back down in the mid-90s now (which is normal for this time of year) and the tap water is cooling off again.

So while I may not make much progress for now, the problem is already passing.

Cheers, Eric

[apistomaster]

A small touch, which may contribute to the production of the simulated rainy season, is to lower the water levels to about 50% and use a powerhead to spray recirculated tank water so that it falls like rains or tributary inputs. This is also a good way to aerate the tank water; well oxygenated water is stimulating to these fish.
Gradually raise water level, using cool water when available.

[bekateen]

A small touch, which may contribute to the production of the simulated rainy season, is to lower the water levels to about 50% and use a powerhead to spray recirculated tank water so that it falls like rains or tributary inputs. Gradually raise water level, using cool water when available.

Nice idea. I've always relied on the first half of your suggestion (i.e., lower tank levels (although never so low as 50%) and let water splash vigorously into tank) to be a stimulant. This actually works well with several frog species too. I've never purposefully did the latter part of your suggestion, the gradual increase in water level... Worth a try.

Thanks,
Eric

[TwoTankAmin]

I would chill water in the fridge. The ideal temp is 35 -38F in one. If you have 3 gals of 38F water and mix it with 7 gals at 80F and you get 10 at 67 F. No ice, no melting, no fancy math.

7 x 80 = 560 plus 3 x 38 = 114. 560 + 114 = 664/10 = 10 gals. at 66.4F.

I suggest you get several clean 1 gal. jugs. I am a cider fan so I repurpose those. Put them into the fridge filled with dechlorinated water the night before and you are good to go the next morning.

I normally am doing water changes for my zebras, for example, to bring them down from as high as 90F in the peak of dry season. I will do a 50% water change with water in the low 70s. and drop the tank about 10 F. The next day I will do that again and get the tank down to between 76 F. During the process of the water changes the heater is turned off and the temp. setting is dropped to 80F when it is turned back on after the wc. The second day I will leave it off for about a half day and then turn it back on. So the coolest temp the tanks will hit is about 75 or 76 from which it will begin to rise from equipment generated heat and then heater generated to get the tank back to 80 within a day overall. I will then drift it back up a few more degrees over the next couple of weeks and hold it there until I have to try a new dry season. I find once a lot of plecos and corys start to spawn they need much less encouragement to keep doing so down the road.

The above ignores anything I do with TDS, food or trying to time the drop to occur with the arrival of a storm and the concurrent barometric pressure drop. It is also what I consider to be the last resort method as it is the most work with no guarantee of success and is, more often than not, unnecessary. As Jools noted, different fish need more or less encouragement. My method is to start by doing the least possible and then upping the routine until it works or I give up.

I think raising the protein content of a diet, feeding well (using live foods is especially good) and then a normal water change done to coincide with a storm is often all it takes. My limited experience in all of this has led me to believe most fish want to spawn so the most important thing we can do is to avoid doing things that work counter to that goal. Avoid poor or improper water conditions, improper diet, wrong tank sizes or setup, etc. etc. Basically, many fish will spawn on their own unless we do things to prevent it.

One man's opinion here, as always.

[bekateen]

I would chill water in the fridge.

That assumes you have open fridge space for 5 gallons of water. I'm out of luck there - I have just one fridge and it's in the kitchen for a reason.

I find once a lot of plecos and corys start to spawn they need much less encouragement to keep doing so down the road.

Yep, that's come up before too. Once the barn doors are opened, eventually the horses are going to escape - and once they do, there's no putting them back. Besides a successful first time spawn with a new species, there's nothing that makes me happier than a failure of a first time spawn. Because once the first spawn is achieved (even if it's a failure), I expect there'll be another, and it's more likely to succeed.

...It is also what I consider to be the last resort method as it is the most work with no guarantee of success and is, more often than not, unnecessary. As Jools noted, different fish need more or less encouragement. My method is to start by doing the least possible and then upping the routine until it works or I give up.

You're spot on with this - You're paraphrasing the old KISS philosophy (Keep it simple, stupid).

I think raising the protein content of a diet, feeding well (using live foods is especially good) and then a normal water change done to coincide with a storm is often all it takes.

Although I always try to make all of my water changes cool ones, I couldn't agree more that a few days of meaty foods (live worms, or steamed clams, etc) followed by a simple WC will do it for most of my fish. Add to that a a week or two of neglect prior to the WC, and you often have icing on the cake.

My limited experience in all of this has led me to believe most fish want to spawn so the most important thing we can do is to avoid doing things that work counter to that goal. Avoid poor or improper water conditions, improper diet, wrong tank sizes or setup, etc. etc. Basically, many fish will spawn on their own unless we do things to prevent it.

I couldn't agree more. I think I've said elsewhere that a spawning fish is a happy fish. In reproductive endocrinology, one thing we're taught is that reproductive function is one of the first functions lost in an animal under stress or illness. That's why a stressful lifestyle is one of the first things a human fertility doctor will enquire about when approached by a new patient struggling with infertility.

Cheers, Eric

[TwoTankAmin]

@bekateen
Just a nit to pick- I suggested 3 gals of cold 38F water, not 5, and that would put your 10 gals of changing water at 67F. But that is actually cooler than you will likely need. You might be able to get away with 2.5 gals depending on how cool your fridge gets the water.

2.5 x 38 = 95 + 7.5 x 80 = 600 695/10 = 69.5 F. How cold do you need your 10 gals of changing water to be?

If you cannot fit 2.5 gals into your fridge, how about buying a few dollar bag of ice, then put it into a container with water and submerge the 1 gal jugs with the changing water up to the neck. A few hours will chill the jug water to where you can use it. (You can probably chill a six-pack at the same time.)

Or- buy a small used fridge just for this task (about $50). Only plug it in when you need the cold water and the electricity costs will be minimized.

[bekateen]

Hi TTA,

Your picked nit is welcome. I overlooked the 3gal detail, and had in my mind a larger volume. But no matter, point taken.

The strategy of adding cool water to the tank is a much more effective strategy than floating iced containers in the tank (as I was doing above) since the cool water mixes almost immediately with tank water, maximizing the temperature change. By contrast, the melting ice strategy absorbs heat from the tank so slowly that it is easily neutralized by the concomitant influx of heat from the surrounding room.

True, it doesn't cost much to buy the next fridge. But that's also one more electrical device in the house, and a rather expensive one at that for the intended purpose. I would go down that road only in the most extreme of situations. I'd rather just wait out the heat wave and allow nature to lower the temperature of the tap water without incurring extra costs.

Cheers, Eric

[Bas Pels]

Besides, a fridge in the house will eventually produce more heat, that is further heaten the house

[TwoTankAmin]

-How much heat will a fridge that is turned on for only a few days every few months generate? On the other hand how much heat is being generated by the spawning tank year round? If one is running a tank at 80F that means it is pushing out that heat all day 24/7 for the most part. If heating the house is that big an issue from using a small fridge a few days a year, how can one run heated tanks year round?
-How much will the fish born because of that fridge sell for down the road? I am sure nobody who spawns catfish keeps all the offspring or even most of them.
-How much room will making under 3 gallons of chilled water take up in one's regular fridge?

And if one does not need the cold water enough times to use a small fridge, then use the ice method I suggested. The only expense there is the container that holds the ice water and the cost of the ice. Think of it like a cooler of beer at the beach

Here is what I would ask. How much will be spent to buy and keep the fish involved in this discussion. How much will it cost to have them in a proper tank, how much heat will that setup generate, how much will be spent to feed and possibly medicate the fish and how much time will be devoted to the project? If this is all about getting the fish because the goal is to spawn them, then $50 for a small fridge and the cost of running it a few days a year seems small. How does it make sense to draw the line where it is being drawn here?

[Bas Pels]

@ how much heat - I understood the topicstarter is now in a heat wave. That is, currently it is hot, but in winter it could well be freezing.

I, in the Netherlands, am in the middle of a rather disappointing summer - thus no such problems. But I would say, the problem is that currently the weather is too hot, and therefroe onew would currently not want to heat the house moore than needed

@ place in the fridge, I would assume that if one would want to replace 3 gallon (12 liters) of cold (say 4 C or 40 F) water a day, that this water will have to stay in the fridge for 36 to 48 hours in order to cool down far enough. And in that case, I would assume one would have to use 12 small containers, of say a quarter of a gallon each.

That is, 6 gallons, and a bit for the shape of the bottles would be needed. That's a quarteor of the room in my frisge (which is, already, full with groceries)

With regard to the cost of the cooling - one can do the math, ending up with, say, spending 50 $ for saving 100 $ of fish. but than, I would say that we bouyght the fish, and therefore have an obligation to care for them. If omne would have to spend 100 $ for saving 50 $ of fish, I would also say - go for it. But I wouild prefer to do it wisely. That is why I wrote the above

[bekateen]

Besides, a fridge in the house will eventually produce more heat, that is further heaten the house

-How much heat will a fridge that is turned on for only a few days every few months generate? On the other hand how much heat is being generated by the spawning tank year round? If one is running a tank at 80F that means it is pushing out that heat all day 24/7 for the most part. If heating the house is that big an issue from using a small fridge a few days a year, how can one run heated tanks year round?
-How much will the fish born because of that fridge sell for down the road? I am sure nobody who spawns catfish keeps all the offspring or even most of them.
-How much room will making under 3 gallons of chilled water take up in one's regular fridge?

And if one does not need the cold water enough times to use a small fridge, then use the ice method I suggested. The only expense there is the container that holds the ice water and the cost of the ice. Think of it like a cooler of beer at the beach

Here is what I would ask. How much will be spent to buy and keep the fish involved in this discussion. How much will it cost to have them in a proper tank, how much heat will that setup generate, how much will be spent to feed and possibly medicate the fish and how much time will be devoted to the project? If this is all about getting the fish because the goal is to spawn them, then $50 for a small fridge and the cost of running it a few days a year seems small. How does it make sense to draw the line where it is being drawn here?

@ how much heat - I understood the topicstarter is now in a heat wave... the problem is that currently the weather is too hot, and therefroe onew would currently not want to heat the house moore than needed

With regard to the cost of the cooling - one can do the math, ending up with, say, spending 50 $ for saving 100 $ of fish. but than, I would say that we bouyght the fish, and therefore have an obligation to care for them. If omne would have to spend 100 $ for saving 50 $ of fish, I would also say - go for it. But I wouild prefer to do it wisely. That is why I wrote the above

Hi All,

Just some personal perspective here: I'm a fish keeper third after father and university professor, and a fish breeder fourth after that. Although I love it when my fish spawn, and honestly I hope they all do eventually (I've said it before, my philosophy is a spawning fish is a healthy fish), spawning the fish for the purposes of sales and profit later on is the last thing on my mind:

In the last four years, I think I've sold fewer than 10 fish for more than $10 USD. Most of my tank-spawned and raised fish have sold for $5 or less, including my

Scleromystax barbatus

,

Centromochlus perugiae

,

Bunocephalus coracoideus

,

Corydoras diphyes

, and of course my clown plecos,

Panaqolus maccus

. Although none of these are "expensive" fish, all of them would retail for more than $5 in stores around here; but of course I'm not a retailer and sales are not a line of revenue for me (and I'm not even counting my common corys (aeneus and trilineatus) or my ABNs because they sell for so little around here).

My point is this: For almost all of these, it will take me at least six months to raise them to what I consider minimum sellable size (1.5" SL for most of those spp). By the time you factor in the utilities to keep the fish (water and electric bills) plus the good quality food I provide over those six months, there is no profit to be made if and when I sell a handful of juvies for those prices (as an aside, I'm also known for giving some away for free). Any money I'd get from such sales is just a pittance, a trivial gesture from the buyers so that they have to contribute some modicum of money which I can put back into the hobby (never mind that for most species I split half of the money with my son, as a reward for his help with tank maintenance). Therefore, although the argument about the cost of running a fridge might be legitimate for a person who actually sells enough fish (in numbers) or who sells expensive fish to make some sliver of profit per fish, the cost of an extra fridge is not justifiable for a person in my situation.

About the "how much heat?" questions and how much heat is being pumped out of the aquaria, "year-round" doesn't matter (to clarify, not that it doesn't matter in the winter, but it doesn't pertain to the OP). Rather, what matters is "right now during the heat wave," and in this case the amount of heat being pumped OUT of the aquaria is very little. In fact, the point I made in an earlier post about heat analysis was that the aquaria aren't heat sources, they're heat sinks - they're absorbing heat from the house in the middle of the extremely hot days when it's so hot outside (even with my AC running), which is only offset by the heat lost due to evaporative cooling from the surface of the tanks (although the tanks are pretty tightly covered, so much of this is negated). It's so hot (sounds like there's a joke there - "How hot is it?"), I've got every aquarium heater in the house unplugged; even so, minimum overnight temperatures in my tanks are about 75-77F because of ambient house temperature combined with the heat generated by power heads and HOB filters with submerged impeller motors.

Another relevant point (and I think Bas Pels brought this up) is that although an extra fridge might not be needed all year round, it will be needed when it's really hot outside (the heat wave). And that's precisely the time that I don't want to go adding heat to the house in order to "cool off" the water. That would be the worst time to run more appliances in the house. Turning the fridge off when it's not hot outside doesn't help either - if anything, you'd like the heat the aquaria when it's cold outside, so more appliances in the house will only warm up the tanks in winter.

Finally, there's the argument of keeping fish alive. Myself, I feel there is a big difference between using extreme measures and added expenses to TRY to spawn fish (which aren't otherwise spawning naturally) versus using extreme measures and added expenses to keep pre-existing fish alive during severe weather. I think we all agree that once we accept fish into our homes as pets, we have an ethical and moral obligation to take responsibility for their welfare. And if we can't provide adequate housing (including proper temperature) for good health (not necessarily spawning), then we shouldn't keep the fish. I've learned that lesson a couple of times in the past, and as a result there are fish I will no longer buy until my housing situation changes to allow universally cooler temps (year-round) in my tanks. If I were to try to start keeping the cool-water species again, a cool basement would be needed or a recirculating water chiller would be necessary (expensive, but I'd just have to count it as a necessary "cost of care" for any cool water species I might try and keep in this house).

This is drifting off the OP a little, which was indeed about a heat wave in my area making it difficult to do cool-water changes to trigger spawnings. The air temps have dropped this week back into the mid 90's F, which is normal, although cold water temps are still in the upper 70's coming out of my taps. Every day or other day, I am still adding the ice-filled containers (2 or 3 18oz-bottles into a 20gal tank) in order to create temporary currents of cool water, but I have no expectation that these are creating long-lasting and significant drops in aquarium temp. The most I can hope for are a few hours worth of cool currents in the tank each day. Let's see if that does any good.

Cheers, Eric

[Shane]

Any money I'd get from such sales is just a pittance, a trivial gesture from the buyers so that they have to contribute some modicum of money which I can put back into the hobby

Wait, there is no money to be had breeding fish? There go my retirement plans
-Shane

[bekateen]

Not the way I (and most people I know) do it.

Shane, please pass that along to the USFWS on my behalf.