Tap/rain water pH troubles with AN pH perfect nutes

I use tap water, which is pretty hard - 0.5 EC (250 ppm?). But if I use rain water which is 0.0001 EC, then in 2 days I get some brown flakes on the surface when I mix nutes (picture below). I use Autopots. If I let pure rain water sit in bucket for one week, this don't happen, so I guess it's something with nutes, mixed solution.
Solution with tap water is set to 6.1 first day, third day is almost 7.5. EC/PPM didn't change much.



Tested rain water also with AN nutes. As I said, flakes on top of water. pH after 2 days is 7.0. First day was 6.1.
EC dropped from 2.25 to 2.2, but I don't think this caused pH to go up.

This of course didn't make troubles in previous soil grows, but now I am in coco and don't want 7.0 water in my reservoir. AN claims anything between 5-8 will be okay because nutes has chelates.. but NPK and non-chelated minerals in nutes will not be absorbed at my pH, I guess. Don't want to test, better stay safe.

Yea, I am looking for some cheap system in another thread, I don't want spend 100€ on RO system because I need only 20-30L of water per week for 2 plants.

Anyone uses AN nutes with tap water? With rain water? Don't check pH in coco? Help here would be great, please.

The AN PH Perfect line is deigned to be used with RO water. Using it with anything else could cause PH issues, depending on what's in the water to begin with. Don't adjust PH, they are formulated so the nutrients are available across a wider PH range. Adding PH adjusters will throw the formula off and cause wild PH swings. I went through this about 2 years ago. Finally went RO and stopped checking PH and my plants started looking much happier, just keep EC levels reasonable.

I only ran it for 2 cycles until I got a better grasp on hydro then went to something I had more control over.

WeedFreak78 said:

The AN PH Perfect line is deigned to be used with RO water. Using it with anything else could cause PH issues, depending on what's in the water to begin with. Don't adjust PH, they are formulated so the nutrients are available across a wider PH range. Adding PH adjusters will throw the formula off and cause wild PH swings. I went through this about 2 years ago. Finally went RO and stopped checking PH and my plants started looking much happier, just keep EC levels reasonable.

I only ran it for 2 cycles until I got a better grasp on hydro then went to something I had more control over.

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So you're saying that my rain water mixed with nutes, which gives me 7.0 pH solution is okay in coco? And don't need pH adjusting to 5.5-6.0?

KonopCh said:

So you're saying that my rain water mixed with nutes, which gives me 7.0 pH solution is okay in coco? And don't need pH adjusting to 5.5-6.0?

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I've never run coco, but from what I've been told by AN and have seen with those nutes, i wouldn't adjust it. I was in DWC and saw PHs from low 5s to high 7s, the veg nutes usually ran more acidic. When I tried adjusting it, they started swinging bad and I couldn't get it under control. According to AN by adding more PH adjusting solution, it throws off the built in PH adjusters. They say all the nutes are chelated do well the PH isn't as critical. Again, getting the EC level matched to the plant helps it stay more stable and closer to the correct ph ranges, but it still fluctuated on me. You could always call AN and ask them, numbers on the bottle, that's what I did.

Your dropping EC and rising PH means you may need to increase your EC level a little. As a general rule:

Dropping EC +rising PH=under fed
Rising EC+ dropping PH= over fed
Steady EC+ dropping PH=slightly over fed
Steady EC + steady or slightly rising PH = about perfect

What AN line are you running, and what order do you mix in? I wonder if the nutes are coming out of suspension because there's no flow to keep things mixed in the passive res.

Hopefully someone familiar with them in coco can chime in.

WeedFreak78 said:

What AN line are you running,

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I"m curious too. If it's micro, grow and bloom (3 part), I'd mix it up using H3AD's formula for Coco.

If not, I'd ditch AN and run Canna Coco. Or a coco specific nute line. maybe Hesi? or house and garden?

I use AN Sensi bloom A+B, Big bud/Overdrive, Bud candy and PK 13/14 which is not from AN.

I know they're pH perfect, but don't know what this means.. Or better say, I think what I think until I saw problems in coco grow.
Also saw video from Youtube, when they're adding AN nutes to (speeking of head) pH 9, pH 7 and pH 5 water. And then all solutions came back to 5.5.

But mine says at 7.0... in tap water (0.5 EC) and in rain water (0.0001 EC).

KonopCh said:

I use AN Sensi bloom A+B, Big bud/Overdrive, Bud candy and PK 13/14 which is not from AN.

I know they're pH perfect, but don't know what this means.. Or better say, I think what I think until I saw problems in coco grow.
Also saw video from Youtube, when they're adding AN nutes to (speeking of head) pH 9, pH 7 and pH 5 water. And then all solutions came back to 5.5.

But mine says at 7.0... in tap water (0.5 EC) and in rain water (0.0001 EC).

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I just looked at ANs site, Sensi has humic/fulvic acids, they really need agitation to stay suspended. Also most of thier supplements have a disclaimer saying they can be used with "ph perfect" nutes, or any other nute line. Bud candy doesn't have that disclaimer. The "ph perfect" nutrients are a system and only really works when you stick to ANs compatible nutrients. It's one reason why I went away from them.

The way it was explained to me is the PH up/down chemical in the nutrients are coated with something. The up is coated with something that only dissolves below a certain ph. When the PH drops, the coating dissolves, releasing PH up. The down is coated with something that only dissolves above a certain ph. When the PH rises, the coating dissolves, releasing PH down. When you add your own PH up/down, it triggers a release of the opposite in the nutrients, and then it jumps around as it tries to balance out again.

We're dealing with chemistry here, understanding how these different chemicals react really helps. Maybe if you mixed the bud candy and pk 13 first, adjust that to 6.5. Then mix the PH prefect nutrients, let them settle for a few minutes, then add the bud candy/ pk13 mixture it might work better.