Water changes

[Steve]

Question I would like to see what you guys think. For two years now I do my normal 70% water change every 2 weeks. Works good for me, no issues. The past couple weeks I had a friend that is a big time chiclid guy tell me that he does "cold water changes". he even sent me a vid which talked about how warm water water changes had issues because of the water going through the hot water tank etc  etc.

Anyone heard of this or thoughts on cold water changes?

[dstuer]

Because my water providers source is Lake Michigan (alkaline), for about 6 months a year, water temps from the tap are in the high 30s to low 40s, and this water is super saturated with oxygen.  Neither of these physical parameters would be good for fish that normally live in mid 70s'F water, if I did a large water change with it.
Even though I use the hot water tap to equalize temp a bit, I add water to my sumps instead of directly to the tank because of the super saturation issue (result...possible gas bubble embolism in fish).  If I draw a glass of water, it clears from the bottom up (micro-bubbles) meaning it is very gas saturated due to cold water temp.
That said, I realize minerals can build up in water heaters, but that is (in part) what the valve on the lower part of the water heater is for.
At least twice per year, I place some sort of container under the low tap of the water heater, and drain out some water.
If it feels viscous (slimy), I drain more until it feels normal.
Not only does this practice keep the mineral buildup out of the fish water, it helps the efficiency of the water heater.
When I worked for the water works, people would call, saying their water felt slimy, I would go check their water heaters, and find for years, they had not drained from the bottom, and the buildup was significant.

[cranialdisturbance]

I always replace tank water with water that is very close to the same temperature.  I am on a well and did have some initial problems with hydrogen sulfide in the water.  I think some was naturally occurring but some was being created in the water heater itself via sulfur eating bacteria and the magnesium anode rod, see link below.  I've mitigated the issue by cranking the hot water heater all the way up, which is supposed to kill the bacteria.  I also use a mechanical / carbon filter on all new water that goes into the tanks.  This has pretty much eliminated the initial problems I was running into.

http://wellowner.org/water-quality/hydrogen-sulfide/ 

[jcunningham0295]

I do water changes every week and replace the tank water with water close to the tank temp.  I put my tap water in 44 gallon rubbermaid trash cans and treat them with salt and prime before they are later pumped into the tank.  I have heard colder water may induce spawning, but have not tried this yet.

[Regalblue]

I try to use as little water as possible from my hot water side.  Besides the potential heavy metal dangers, there is still the fact that I live with 3 females & there's always a demand for hot water.

 Here's a good video on the subject...
AquaticMadness Talks about WARM WATER water chang…: http://youtu.be/SGndKpJQxEY

[Regalblue]

Follow up video (includes some quarantine talk)
 AquaticMadness adds a bit more: http://youtu.be/OqeRgErjyTo

[Ron]

Before this thread, I had never heard about draining a hot water tank to help maintain it. Good to know!

I think the 70% is overkill. I do 50% myself.

I've heard of doing cold water changes in the context of trying to trigger fish to spawn. I haven't tried it myself. The biggest concern IMO is filling the tank cold enough, but not too cold. Monitoring the temperature seems like a bit of a PITA.

I try to keep the temperature close to the tank temp when filling. I run a garden hose from a utility sink with separate hot and cold controls. Because of how many gallons I'm refilling, I have to adjust the temperature a few times throughout the refilling process.

I have one done a water change with rather warm water. I was setting up a new 150 and wanted to make sure it was going to be warm enough, because a lot of the rockwork going into it was cold (I figured things would balance out after an hour or so). After the fish had been in the tank for a half hour or so, they were gasping for air. Warmer water holds a lower O2 concentration. I threw in a 12" airstone to rectify the O2 content problem. Now I try to avoid doing water changes with water much warmer than the tank temperatures.

[merritt]

My water supply too is from Lake Michigan with the same parameters stated above. Unfortunately i am not a homeowner and have little control over changing the standards. With this said i change my tanks at least twice a week with a 30 to 40 percent change. I fill this change with cold water everytime in the summer and my fish love it. Obviously in the winter i can't use total cold water and i have to warm it. I'd say the water temp of my changes year round average about 40 to 43 degrees year round. The total drop in tank temp from start to finish is about 6  degrees. I can also understand why some breeders use their changes for stimulation.

[reefried]

I would say if you are worried about the hot water from the water heater fill a tub or some tubs with cold water a day before your water change and bring the temp up with a heater before changing it out. I used to do this with my reef tanks as I was using RO filtered water from the cold side.