Very high EC tap water, what should I do?

I was about to mix up my first ever nutrient solution for some seedlings, lucky I measured the tap water before I did.

pH 7.9 and EC 0.9!

Seeing as though I was about to transplant the jiffy pellets into solo cups, pre-fertigate the coco and give them their first feed at EC 0.8 or less, I have no idea what to do now. Short of setting up the RO system or buying distilled water, I'm stumped on where to go from here. The shops are closed until tomorrow, and the RO system is at a friends house rn and may need replacing. Cotyledons are open, and the roots are poking through some of the jiffy pellets that are drying out and getting quite light- they need at least a watering right now.

Should I just water them with plain pH'd tap water for now, and try to get a RO system asap, maybe pick up distilled water tomorrow until I have the RO system up and running? Timing couldn't be worse. Any advice will be much appreciated!

Sorry i don't have any advice for you because i'm a beginner and growing in soil. But isn't there a gas station that works 24/7 where you can buy bottled water? I suppose it's softer than tap. Or maybe they have distilled water also. Or water from a dehumidifier if you have.

VictorFlorez said:

I was about to mix up my first ever nutrient solution for some seedlings, lucky I measured the tap water before I did.

pH 7.9 and EC 0.9!

Seeing as though I was about to transplant the jiffy pellets into solo cups, pre-fertigate the coco and give them their first feed at EC 0.8 or less, I have no idea what to do now. Short of setting up the RO system or buying distilled water, I'm stumped on where to go from here. The shops are closed until tomorrow, and the RO system is at a friends house rn and may need replacing. Cotyledons are open, and the roots are poking through some of the jiffy pellets that are drying out and getting quite light- they need at least a watering right now.

Should I just water them with plain pH'd tap water for now, and try to get a RO system asap, maybe pick up distilled water tomorrow until I have the RO system up and running? Timing couldn't be worse. Any advice will be much appreciated!

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Are plants outside watered with this water doing well? If so just start using it. Access the water report. They’re usually posted online. Post those results here for better advice.

OM2 said:

Sorry i don't have any advice for you because i'm a beginner and growing in soil. But isn't there a gas station that works 24/7 where you can buy bottled water? I suppose it's softer than tap. Or maybe they have distilled water also. Or water from a dehumidifier if you have.

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I might have to give them a call and see if they have any distilled water in stock. I want to start feeding them and I cant think of any other way to do that atm without the EC getting too high. It already seems a little too high and I haven't even put anything in. Thanks for the reply.

hotrodharley said:

Are plants outside watered with this water doing well? If so just start using it. Access the water report. They’re usually posted online. Post those results here for better advice.

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The plants outside stay alive with the tap water, but I wouldn't say they do well with it, earlier this year when watering the garden from the tap. At the moment it's raining every couple of days so the plants outside don't get any water from the tap, and are doing better.

Sorry, I'm not sure I understand. I want to start giving them nutrients, the main resource I'm using https://www.cocoforcannabis.com/how-to-grow-cannabis-seedlings-in-coco-coir/ says that now is the time to start doing it, how can I use this water when the EC is already higher than my target for seedlings?

I germinated the seeds in jiffy pellets with the tap water, and they seem to be ok for now, slightly faded yellowish cotyledons on a couple of them but I assumed that could be because the pH is rather high and they still have nothing but plain water.

i used to buy RO water from walmart in 5 gallon jugs when i was first starting out. then i gradually switched over to my well water (mine is only 0.2 though)

I think you need a better meter

Or just start with a ¼ strength feed and keep goin up by a quarter each week. Watch for signs.Stop at ¾⅘ if you get that high.

rkymtnman said:

i used to buy RO water from walmart in 5 gallon jugs when i was first starting out. then i gradually switched over to my well water (mine is only 0.2 though)

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That's commitment! Buying RO water 5 gal at a time for an entire grow sounds like a bit of a hassle. I certainly don't want to have to buy water until I can feed above 0.9.

ProPheT 216 said:

I think you need a better meter

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The meter is fine. It's calibrated and accurate. The tap water really is EC 0.9, I found it hard to believe too but it's true.

ProPheT 216 said:

Or just start with a ¼ strength feed and keep goin up by a quarter each week. Watch for signs.Stop at ¾⅘ if you get that high.

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The issue is that EC 0.8 is really the highest I want to go atm, and the water already reads above that without any added nutrients. Even a "1/4 strength feed" would be pushing EC higher than 0.9. Are you suggesting I add the nutrients at a quarter of my desired amount- as in, what would be EC 0.2 with distilled water, and use my tap water for a total EC of 1.1/1.2?

U can get water in bottles try to get low sodium stuff cos common salt can mess with your plants too unless you buy ro water instead or get a ro machine

You won't need calmag.

Just pretend your water is .1 ec and move on with gradually increasing feed strength. Don't over think this

VictorFlorez said:

That's commitment! Buying RO water 5 gal at a time for an entire grow sounds like a bit of a hassle. I certainly don't want to have to buy water until I can feed above 0.9.

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you might not need to feed above 0.9 at all.

and it also eliminates water as a potential problem. starting off, there will be plenty of other things to worry about

xtsho said:

You won't need calmag.

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So the high EC from the tap is likely to include decent amounts of cal and mag? That's good news. I might try to find the water report as @hotrodharley suggested. The nutrient line (HY-GEN CocoGrow) doesn't have a calmag additive, there's cal and mag in the base nutes and other additives such as the humic+fulvic acid "humibooster", so I was probably never going to use any sort of calmag other than epsom salts if the plants ever ask for extra mag..

ProPheT 216 said:

Just pretend your water is .1 ec and move on with gradually increasing feed strength. Don't over think this

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Sorry I can't help it, I'm an overthinker.

...Pretend my water is EC .1? Really? So if I want to give them nutrients at EC 0.8 as planned, I will end up feeding my seedlings EC 1.7 and this is fine? I'm really not sure about that, unless there's something I'm not getting and you can explain it to me.

At this point I still feel I might need to buy some distilled water for now, and then get the RO set up asap. Use at least 3/4 RO, 1/4 tap maybe.

rkymtnman said:

you might not need to feed above 0.9 at all.

and it also eliminates water as a potential problem. starting off, there will be plenty of other things to worry about

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0.9 is pretty high, I'm surprised the seedlings didn't get burned. There must be something I'm not getting, I've seen an RO grow coasting along nicely during full flower at EC 1.1.

buy a ro system. Makes for good drinking water too

My tap water is 7.5PH and 0.7EC. If you have an AC and dehumidifier you can mix some of this 0EC condensate water with your tap water to bring it down to reasonable numbers. You can get RO but you will be changing your filters frequently not to mention the huge waste of water those systems are.

i wouldn't worry too much you can still give good feedings even with a 0.9 starting EC. And you can also feed more often to compensate for have less of a nutrient EC in the water.

VictorFlorez said:

0.9 is pretty high, I'm surprised the seedlings didn't get burned. There must be something I'm not getting, I've seen an RO grow coasting along nicely during full flower at EC 1.1.

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i never went above 1 to 1.2 in dwc. in coco, i feed at 0.5 a few times a day.

VictorFlorez said:

0.9 is pretty high, I'm surprised the seedlings didn't get burned. There must be something I'm not getting, I've seen an RO grow coasting along nicely during full flower at EC 1.1.

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.9 EC for hydro is far from ideal, you really should view a water report to see what's in there.
Even if purely Ca and Mg in the proper ratios (which it won't be), that's far too much

Dilute to .3 EC with some RO

VictorFlorez said:

0.9 is pretty high, I'm surprised the seedlings didn't get burned. There must be something I'm not getting, I've seen an RO grow coasting along nicely during full flower at EC 1.1.

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It will be fine to use your tap water once you pH it but over time the mineral salts in your water will build up in your soil causing problems so you'll want plenty of runoff at each watering or use RO water like I have been using since I moved up here to northern Alberta in '01. The tap water in town was bad enough then we bought the acreage almost 20 years ago and our tap water comes from a dugout on the property and it's basically the same as yours with added microbes the plants like but aren't good for drinking.

We water our outdoor plants with the tap water but rain dilutes and pHs the water so the plants grow fine. Rain water is always lower than 7 and virtually distilled water for free tho distilled and good RO water has no real pH of it's own people keep checking it and coming up with high or low numbers that are meaningless.

Every Friday when I go to town I buy 5 - 5gal jugs of RO water for $3.49 each but one of these days I'll set up the RO system I bought a year ago for over $500. With town water just a basic 3 - stage unit for $150 would do but as our water needs extra filtration and sterilization with a UV filter it was a lot more but should pay for itself in 4 - 5 months.

For long term you should get your own RO unit and save future grief and cash.

MidnightSun72 said:

My tap water is 7.5PH and 0.7EC. If you have an AC and dehumidifier you can mix some of this 0EC condensate water with your tap water to bring it down to reasonable numbers. You can get RO but you will be changing your filters frequently not to mention the huge waste of water those systems are.

i wouldn't worry too much you can still give good feedings even with a 0.9 starting EC. And you can also feed more often to compensate for have less of a nutrient EC in the water.

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I know what you mean about RO wasting water, I bought one for the fish tank which I no longer have, my friend is borrowing it rn. I used to turn the tap off on the toilet and fill the cystern with the RO waste water. Seeing all that water go down the drain didn't feel right.

Thanks, the high EC tap water obviously isn't a total dealbreaker as the seeds germinated and are still doing ok, but I think diluting some will definitely be the way to go.

Billy the Mountain said:

.9 EC for hydro is far from ideal, you really should view a water report to see what's in there.
Even if purely Ca and Mg in the proper ratios (which it won't be), that's far too much

Dilute to .3 EC with some RO

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Thank you for the advice, I had a feeling this would be the case. I'm going to buy some distilled water for now since a 5/10L bottle of it should last me a while at this early stage, and I'll organise the RO asap.

rkymtnman said:

i never went above 1 to 1.2 in dwc. in coco, i feed at 0.5 a few times a day.

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Wow 0.5, that would be good on the hip pocket for nute costs. The higher frequency / lower EC thing is what @MidnightSun72 was saying too, maybe in the future when I can set up an automated watering system this might be more doable for me.

OldMedUser said:

It will be fine to use your tap water once you pH it but over time the mineral salts in your water will build up in your soil causing problems so you'll want plenty of runoff at each watering or use RO water like I have been using since I moved up here to northern Alberta in '01. The tap water in town was bad enough then we bought the acreage almost 20 years ago and our tap water comes from a dugout on the property and it's basically the same as yours with added microbes the plants like but aren't good for drinking.

We water our outdoor plants with the tap water but rain dilutes and pHs the water so the plants grow fine. Rain water is always lower than 7 and virtually distilled water for free tho distilled and good RO water has no real pH of it's own people keep checking it and coming up with high or low numbers that are meaningless.

Every Friday when I go to town I buy 5 - 5gal jugs of RO water for $3.49 each but one of these days I'll set up the RO system I bought a year ago for over $500. With town water just a basic 3 - stage unit for $150 would do but as our water needs extra filtration and sterilization with a UV filter it was a lot more but should pay for itself in 4 - 5 months.

For long term you should get your own RO unit and save future grief and cash.

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Thanks @OldMedUser , I was thinking since we are in the wet season I could try collecting some rain water to supplement the tap water, my only concern was whether or not this could cause any issues with coco, but I don't think it would. They say botrytis occurs more often with plants exposed to rain water, but if I don't use it for foliar sprays, I don't see what harm it could do. Rain water tastes best imo.