When filling my tank, is warm tap water a bad idea?

[Thunder84]

I have always been told not to drink (or cook with) warm tap water because it can contain bacteria, copper and other stuff.

But is it ok to use moderately warm tap water for my plants? Of course cold tap water ought to be the best but it is really cold where I live (the roots won't like it) and it takes a looong time for it to warm up to room temperature.

Anyone who has any thoughts on this?

 

[Trend]

Cut it with hot water. Its what I do.

 

[WelderDan]

I'm assuming you a referring to the hot water from your water heater. It's not recommended to use hot water from your water heater to cook with or drink because lime, calcium, rust, copper and other crap accumulate in the tank, especially on the electrodes of electric water heaters.

If you shouldn't drink it, you shouldn't use it on your plants.

I'd recommend boiling a gallon or so and cutting your cold tap with that.

Note I didn't call it a "hot water heater." Why would you heat hot water?

 

[mowood3479]

Draw it into buckets.. N let it sit in ur room for a day until it warms too room temp

 

[ortsa1]

dont get hung up on such minuscule things

your most important thing is going to be having a/c and being able to bring your temp/humidity to the right levels next being enough light

and plant genetics everything else is just things you can worry about when you are bored

 

[Snow Crash]

Wow...

Okay guys. It's time to drop some knowledge.

I'd like to introduce you all to a little concept known as Dissolved Oxygen Capacity.

Using warm water is a bad idea. Not just because of the whole hot water heater buildup thing. It's a bad idea because increased root zone temperatures contain reduced oxygen levels and create an ideal habitat for pathogens and disease to take hold. Many, many, people confuse Nitrogen Toxicity (eagle claw) with Epinasty (downward curl from insufficient rootzone O2).

What you can see from the image above is that that when you move from the ideal range of 17c to 22c (9-10 mg/L) to a warm temperature of 30c+ that you lose in excess of 10% of the DO capacity. Moving from a potential 10 mg/L to under 8mg/L doesn't sound like a whole lot on paper, but it represents more than 20% less oxygen to the root zone and that can be the difference maker between a healthy root zone and a struggling one.

Ideal root zone temperatures are between 17c (62f) and 21c (72f). This is very important indoors, especially in hydroponic reservoirs, but also for organics.

 

[Trend]

DO is important but not as much in coco. You don't want to feed ice water to them period. Long as you're under 74 or so you're fine. As far as toxic that's laughable. I cook with hot water all the time I'm still alive so are my plants lol. You don't need much just make sure its not cold.

 

[Crusader Rabbit]

I've dealt with some hot water tanks that had active bacterial colonies. This seems worse in water with a high mineral content, especially sulfur. Turn on your hot water and you get a rotten egg smell. Drain the tank and a bunch of nasty black sludge comes out off the bottom.

If you don't have this then you're probably fine. After all, plants normally grow in dirt don't they? I think the biggest worry would be introducing a slew of chemical salt feeding bacteria into your nutrient reservoir. That could create a nasty bacterial bloom you don't want to deal with.

For the same reason you should avoid using empty milk jugs to mix nutes for plants that are in a reservoir based watering system, or will soon be. I just found this out. You don't want your nute reservoir going cloudy and smelling like spoilt milk.