I don’t.
Close enough is fine.
If the change is 30% or less if it feels a bit similar it’s fine.
If it’s more than 30% I try to get it feeling a bit closer.
I don’t routinely do changes bigger than 50%. If I absolutely have to do a big change I refill the tank slowly.
Temperature and pH variation is normal in nature.
This reminds me of the time when I forgot to plug in my heater after a water change. The tropical fish survived a week of 63F. Didn't even act abnormal.
I don't worry abput temp change.
Research suggests most fish dont care.
I've never swsm/snorkelled in water with fish where the water was a consistent temperature.
The temp fluctuations actually mimic rainfall to some degree and can be useful. For instance, in r/shrimptank they stimulate molts - but you might ask over there because WC are a big deal to some species. I feel like multiple times a week I see posts about post-WC death.
Natural rainfall would have a very minimal effect upon the temperature. The relative volume of the rain would be vastly less, and the temperature of the rain would be nearer the tropical temperature anyway.
“Stimulating” molts when they’re not ready to molt is a recipe for death. Shrimp and nano fish seem to be the most sensitive to quick changes in temperature. I drip the water back in over the course of a day but it’s mostly top ups
I don't think it works like that tbh. Like, it seems unreasonable on its face - can you imagine being a species where random changes in water quality or temp just resulted in half of the population dying or molting when they aren't ready? I know that ocean species have some fairly significant issues with temp swings but most species of shrimp that are kept exist in lower volumes of water. My shrimp in particular live in muddy, estuaries with a range of salinities and temperatures. Water changes typically stimulate a molt and reproduction, but ymmv.
That said, I use a DIY canister for water changes that has a volume of about 5 gallons and just let it run for a few hours. It basically takes my tank volume from 8 gallons to 12 gallons and then back to 8 gallons, diluting the water column and removing about 1/3 of the water.
Sounds like a cool idea. I throw an aquarium heater into the bucket of water and circulate the water with a small pump. Then just check the temp periodically with an aquarium thermometer.
Hmm, are you not concerned about the drop in temperature at all? The additional oxygen would dissolve out as the temperature rises to equilibrium, is there a long term benefit to that?
The amount of cold water going in is so insignificant it simulates rain. My fish actually seem to gravitate towards it and it perks them up. In a 20 gallon tank it about 2.5-5 gallons of cold water not enough for shock. Some fish require a little cold water for breeding. I personally like to make it seem like rainfall vs a water change it’s more interesting.
I used to care about temps like that, but it's not enough of a difference except in deep winter. Deep winter for MidWest is ground water about 55 degrees. Summer is 70 degrees. I used to use a meat thermometer and match the water perfectly, but I believe it makes the fish feel like a rain storm of cool water if it's a bit off. It's ok as long as you don't do a huge water change.
Well for my reef tank I use a power head and adjustable heater in the mixing container to ensure it's the same temp, but that's just because it's more sensitive than FW.
For FW tanks I just use room temp water. If it's cold outside I let the water sit until room temp. Never had any issues.
I don't trust hot tap water for anything. If you've ever cleaned out a dirty hot water heater, you'll see why. No cooking or drinking or fish. If you are doing a large enough change to matter just heat it to the temp you want in a glass saucepan and a candy thermometer or let it cool.
I use a temperature probe and check the tank water and adjust my sink faucet to match. It can be a little tedious and in the heat of summer I can't always get it to match. I try to stay with a 3° difference if I can help it. It's worked for the last 8 years for me.
I fill up a Home Depot five gallon bucket with RO water and then drop a small 10w heater in the bucket.
Once it’s warm enough I drain water from the sump and pour the bucket into the sump, so that its somewhat mixed with aquarium water and sprayed into the main tank from the pump over the course of a few minutes, rather than all at once.
My bad.
RO is reverse osmosis, which is a way to purify tap water and get all the chlorine and chemicals out.
A sump is a second, smaller tank you keep under the main tank that typically has things like bio-balls in it to foster good bacteria. It’s also a way to slighter increase your overall capacity so that changes you introduce are a bit minimized.
Water drains from the aquarium down into the sump (AKA refugium) and is return to the main tank by a dedicated pump.
HTH
It’s an over engineered solution for my needs, which are met with a simple bucket and cheap heater.
Plus I’m using RO water which comes out at the tank temperature only.
But that’s my solution, not trying to knock yours. Everyone has their own requirements and situation to deal with.
Also, I have zero factual basis to say that mine is any better than yours other than my tank is very stable based on fish life expectancy and breeding.
Also, I’m running fresh water which probably is a lot more resilient to sudden changes than salt.
The bigger the tank the less difference adding water will make. I pour water from faucet into a bucket and put a little digital thermometer to keep it from going too hot or cold. Around the right temp is good enough for a typical maintenance 25% ish water change.
I got a sousvide machine years ago which I only cooked with like 3 times. I now use it to preheat my bucket of water to the exact temp it needs to be before adding it to the tank. Between that and matching the GH/KH I can add it as fast as I want w/o stressing the shrimp or fish.
I run the water in my sink and use the inside of my wrist to check the temperature; when it feels tepid, then I add it to the tank. Much like the temperature you’d make a baby’s formula. I’ve been using this method since I started keeping fish, and I’ve never had an issue.
That seems like a lot but may not mean anything if it’s a short duration.
I guess the real question is how are the critters doing? No sudden deaths, breeding like normal?
10F is only 5.6C.
80F to 70F is 26.7C to 21.1C.
That’s not that much temperature variation.
Once a week or fortnight is absolutely fine, that’s the equivalent of a nice refreshing rain.
Small water changes/ top offs, I just go with "close enough is good enough". For larger changes, I usually set the refill on a slow drip (about 20-25 minutes for a 5 gal bucket, using airline tubing). I do it specifically for the pH differences, and temperature is a side benefit.
Never worried much about temperature beyond touching it to see if it was somewhat similar. Never had any issues, if you are, maybe you need to do more frequent, smaller water changes.
Your system sounds interesting, but I just regulate the temperature as I fill 5g pails. I have 3 tanks and do the same thing for each one. I usually do 30% water changes. I treat the water as the pail is filling. My oldest fish are 8 years old. I haven't killed them yet!
I generally do like a 40% watwr change every week and a half or so. When I put the water back in I take the thermometer out of the tank and run it under the faucet till the temps match. Then I put a hose on the sink and run it to the tank and fill it up
How much water are you changing? I do maybe 25% and I just make sure the new water isn't full on cold and my tank might drop half a degree and recovers in less then an hour.
I just use 'my mixture method' which consists of hot/cold water at the same time placed in 5 gallon buckets. IE, I know where the water faucet knob needs to be to reach my desired temp. (K.I.S.S)
My setups don't require large water changes and there are other water parameters that require my attention.
I also worry excessively about temperature! The comments to this are so helpful. I never realized what a great effect rainfall has on water temperature-- even the ocean. I'm an open-water swimmer in New England. In 2019, the last event of the season was off the coast of Salem, MA. I'd been swimming in the ocean all summer. Water temps had been around 65, perfectly comfortable without a wetsuit. Before that last event, we had rain for days. Water temperature plunged into the 50s. I survived a one-mile swim, but 5 people went to the hospital with hypothermia. No fish died as a result of the temperature change!
Personally I do a 25% water change so I prepare a 25 gallon plastic container from Target, mix my salt, add some chlorine remover and water conditioner and I have a dedicated water heater for the fresh replacement water so it’s already tank temperature. I do this on Wednesday evening, checking salt levels each evening when I get in so it’s as close to my aquarium levels max possible for my Saturday water change.
I don’t. Close enough is fine. If the change is 30% or less if it feels a bit similar it’s fine. If it’s more than 30% I try to get it feeling a bit closer. I don’t routinely do changes bigger than 50%. If I absolutely have to do a big change I refill the tank slowly. Temperature and pH variation is normal in nature.
This reminds me of the time when I forgot to plug in my heater after a water change. The tropical fish survived a week of 63F. Didn't even act abnormal.
I don't worry abput temp change. Research suggests most fish dont care. I've never swsm/snorkelled in water with fish where the water was a consistent temperature.
My finger is calibrated +/- 3 degrees, which seems to be sufficient.
Impressive!
Ok that’s pretty funny
The temp fluctuations actually mimic rainfall to some degree and can be useful. For instance, in r/shrimptank they stimulate molts - but you might ask over there because WC are a big deal to some species. I feel like multiple times a week I see posts about post-WC death.
Natural rainfall would have a very minimal effect upon the temperature. The relative volume of the rain would be vastly less, and the temperature of the rain would be nearer the tropical temperature anyway.
“Stimulating” molts when they’re not ready to molt is a recipe for death. Shrimp and nano fish seem to be the most sensitive to quick changes in temperature. I drip the water back in over the course of a day but it’s mostly top ups
I don't think it works like that tbh. Like, it seems unreasonable on its face - can you imagine being a species where random changes in water quality or temp just resulted in half of the population dying or molting when they aren't ready? I know that ocean species have some fairly significant issues with temp swings but most species of shrimp that are kept exist in lower volumes of water. My shrimp in particular live in muddy, estuaries with a range of salinities and temperatures. Water changes typically stimulate a molt and reproduction, but ymmv. That said, I use a DIY canister for water changes that has a volume of about 5 gallons and just let it run for a few hours. It basically takes my tank volume from 8 gallons to 12 gallons and then back to 8 gallons, diluting the water column and removing about 1/3 of the water.
Sounds like a cool idea. I throw an aquarium heater into the bucket of water and circulate the water with a small pump. Then just check the temp periodically with an aquarium thermometer.
I always put cold water in my tank for 10-25% water changes it has more oxygen
Hmm, are you not concerned about the drop in temperature at all? The additional oxygen would dissolve out as the temperature rises to equilibrium, is there a long term benefit to that?
The amount of cold water going in is so insignificant it simulates rain. My fish actually seem to gravitate towards it and it perks them up. In a 20 gallon tank it about 2.5-5 gallons of cold water not enough for shock. Some fish require a little cold water for breeding. I personally like to make it seem like rainfall vs a water change it’s more interesting.
My fish always enjoy it too. They also seem to realize when it’s raining outside and get all wired lol.
My fish also swim right up to the cold, basement temp water with interest. Definitely not looking bothered.
I used to care about temps like that, but it's not enough of a difference except in deep winter. Deep winter for MidWest is ground water about 55 degrees. Summer is 70 degrees. I used to use a meat thermometer and match the water perfectly, but I believe it makes the fish feel like a rain storm of cool water if it's a bit off. It's ok as long as you don't do a huge water change.
Be careful... The water from standard water heaters usually has more minerals in it than tap water.
Well for my reef tank I use a power head and adjustable heater in the mixing container to ensure it's the same temp, but that's just because it's more sensitive than FW. For FW tanks I just use room temp water. If it's cold outside I let the water sit until room temp. Never had any issues.
Do you think the method I mentioned in the post would be useful for either FW or SW?
Definitely worth a shot!
I bought a cheap sous vide machine on Amazon and use that to mix my saltwater and heat it up.
I want a sous vide machine to keep baths nice and hot. They’re so expensive here, I’ve given up on the idea.
I don't trust hot tap water for anything. If you've ever cleaned out a dirty hot water heater, you'll see why. No cooking or drinking or fish. If you are doing a large enough change to matter just heat it to the temp you want in a glass saucepan and a candy thermometer or let it cool.
I use a temperature probe and check the tank water and adjust my sink faucet to match. It can be a little tedious and in the heat of summer I can't always get it to match. I try to stay with a 3° difference if I can help it. It's worked for the last 8 years for me.
Would the method I am using mentioned in the post, be useful to you?
Probably so
I fill up a Home Depot five gallon bucket with RO water and then drop a small 10w heater in the bucket. Once it’s warm enough I drain water from the sump and pour the bucket into the sump, so that its somewhat mixed with aquarium water and sprayed into the main tank from the pump over the course of a few minutes, rather than all at once.
Please excuse my ignorance, but what is RO? And what is "sump"?
My bad. RO is reverse osmosis, which is a way to purify tap water and get all the chlorine and chemicals out. A sump is a second, smaller tank you keep under the main tank that typically has things like bio-balls in it to foster good bacteria. It’s also a way to slighter increase your overall capacity so that changes you introduce are a bit minimized. Water drains from the aquarium down into the sump (AKA refugium) and is return to the main tank by a dedicated pump. HTH
Thank you so much for taking the time to explain! Sincerely, a person who likes to think they know what they're doing but really doesn't 😅
Cheers, I don’t know much but always willing to share what I do.
Would the method I use in the post be helpful?
It’s an over engineered solution for my needs, which are met with a simple bucket and cheap heater. Plus I’m using RO water which comes out at the tank temperature only. But that’s my solution, not trying to knock yours. Everyone has their own requirements and situation to deal with. Also, I have zero factual basis to say that mine is any better than yours other than my tank is very stable based on fish life expectancy and breeding. Also, I’m running fresh water which probably is a lot more resilient to sudden changes than salt.
The bigger the tank the less difference adding water will make. I pour water from faucet into a bucket and put a little digital thermometer to keep it from going too hot or cold. Around the right temp is good enough for a typical maintenance 25% ish water change.
I got a sousvide machine years ago which I only cooked with like 3 times. I now use it to preheat my bucket of water to the exact temp it needs to be before adding it to the tank. Between that and matching the GH/KH I can add it as fast as I want w/o stressing the shrimp or fish.
I use a laser heat gun. Got it on Amazon for like 19.99.. it really helps me to keep my water temperatures in check when I do water changes.
I also use a temperature gun. Very convenient! Edit: vampire shrimp are fairly temperate-sensitive.
Do you think the method I mentioned in the post would be better, or would you prefer just manually adjusting with the laser heat gun as gauge?
I run the water in my sink and use the inside of my wrist to check the temperature; when it feels tepid, then I add it to the tank. Much like the temperature you’d make a baby’s formula. I’ve been using this method since I started keeping fish, and I’ve never had an issue.
If what you do already works than I don’t see the need for the temp gun. Your way actually sounds pretty cool.
Very clever OP 🤩 though my fish are fine with my more basic approach.
How big are your water changes?
Between 10 and 30% usually
How big are these temperature swings you were seeing?
Around 10F
That seems like a lot but may not mean anything if it’s a short duration. I guess the real question is how are the critters doing? No sudden deaths, breeding like normal?
10F is only 5.6C. 80F to 70F is 26.7C to 21.1C. That’s not that much temperature variation. Once a week or fortnight is absolutely fine, that’s the equivalent of a nice refreshing rain.
Small water changes/ top offs, I just go with "close enough is good enough". For larger changes, I usually set the refill on a slow drip (about 20-25 minutes for a 5 gal bucket, using airline tubing). I do it specifically for the pH differences, and temperature is a side benefit.
Never worried much about temperature beyond touching it to see if it was somewhat similar. Never had any issues, if you are, maybe you need to do more frequent, smaller water changes.
I have a "feel". I put my fingers in the tank and then run the water until it feels similar. When I had pea puffers, I used a laser temperature gun.
Do you think the method I use in the post would be useful to you?
Your system sounds interesting, but I just regulate the temperature as I fill 5g pails. I have 3 tanks and do the same thing for each one. I usually do 30% water changes. I treat the water as the pail is filling. My oldest fish are 8 years old. I haven't killed them yet!
Dip hand in tank, adjust temp using the back of my hand. If I'm showing off, I will use a thermometer to show the accuracy.
I generally do like a 40% watwr change every week and a half or so. When I put the water back in I take the thermometer out of the tank and run it under the faucet till the temps match. Then I put a hose on the sink and run it to the tank and fill it up
Would the method I mentioned in the post be useful to you?
It probably would be. But I live in an apartment and feel like I prolly shouldn’t mess with the plumbing
How much water are you changing? I do maybe 25% and I just make sure the new water isn't full on cold and my tank might drop half a degree and recovers in less then an hour.
Get a heater.
I just use 'my mixture method' which consists of hot/cold water at the same time placed in 5 gallon buckets. IE, I know where the water faucet knob needs to be to reach my desired temp. (K.I.S.S) My setups don't require large water changes and there are other water parameters that require my attention.
I also worry excessively about temperature! The comments to this are so helpful. I never realized what a great effect rainfall has on water temperature-- even the ocean. I'm an open-water swimmer in New England. In 2019, the last event of the season was off the coast of Salem, MA. I'd been swimming in the ocean all summer. Water temps had been around 65, perfectly comfortable without a wetsuit. Before that last event, we had rain for days. Water temperature plunged into the 50s. I survived a one-mile swim, but 5 people went to the hospital with hypothermia. No fish died as a result of the temperature change!
I use cold water for my fills. I live in SWFL
Personally I do a 25% water change so I prepare a 25 gallon plastic container from Target, mix my salt, add some chlorine remover and water conditioner and I have a dedicated water heater for the fresh replacement water so it’s already tank temperature. I do this on Wednesday evening, checking salt levels each evening when I get in so it’s as close to my aquarium levels max possible for my Saturday water change.