Struggling to maintain pH, Coco ebb and flow

[Red October]

My ph keeps rising and I don't know how to combat it, seems to be a common thing with Coco and it's runoff but I'm doing an ebb and flow setup and my runoff is basically the main watering source I'm using tap water filtered through an under counter filter and I can get my ph to the correct level with basically just the nutes but the ph starts creeping up. I can control it with some vinegar but that means I need to add more each time before watering but that also increases the EC value gradually.

I scrub my tank once a week with some bleach just to make sure I keep algae growth under control and the plants are doing great, even with the water at the higher ph I don't notice any slow down or feeding issues, fan leaves are super healthy and green and the leaves are always praising Jah but would like to hear if there's something I could do to stop the ph creep.

 

[aliceklar]

Its not a bad thing for pH to fluctuate a bit within the range as it gives plants a chance to absorb different groups of nutes. Some things can get locked out at low pH (P & Mg), some at high (esp Calcium). If the pH floats through the range it means the plants can get everything they need. For coco, you should use the hydro range - between 5.5 and 6.1 - so if you are putting in at around pH 5.5 and it has crept up to around 6 or slightly above when it comes out, thats perfect. Do you have v hard tapwater? That can cause issues with rising pH and high ppm/EC (organic acids like vinegar or citric dont cut it on their own - they only lower pH temporarily). If so, I'd recommend getting some proper pH down - either based on phosphoric or nitric acid.

 

[Red October]

Its not a bad thing for pH to fluctuate a bit within the range as it gives plants a chance to absorb different groups of nutes. Some things can get locked out at low pH (P & Mg), some at high (esp Calcium). If the pH floats through the range it means the plants can get everything they need. For coco, you should use the hydro range - between 5.5 and 6.1 - so if you are putting in at around pH 5.5 and it has crept up to around 6 or slightly above when it comes out, thats perfect. Do you have v hard tapwater? That can cause issues with rising pH and high ppm/EC (organic acids like vinegar or citric dont cut it on their own - they only lower pH temporarily). If so, I'd recommend getting some proper pH down - either based on phosphoric or nitric acid.

Thanks for that, it seems we have slightly hard water that varies from 17 – 60 mg/l as CaCO3 from the cities report (I don't know what that actually means though), but I was wondering about the longevity of vinegar in the solution, I'll get some proper ph down and see if that helps the issue, my ph goes upto 6.5 by the end of the week but the EC value stays about the same

 

[f-e]

Vinegar is quite useless, and 17-60ppm is soft water. If you are on the low end of that, it's not hard enough to offer good buffering, and in coco, that's even more of a problem. Are you loading up with maybe 2ml/L calmag?

 

[Bush Dr]

Don’t use vinegar in coco, use phosphoric acid, your ph will be more stable …if you have an air line in (which you should have) then that’ll raise it a point or 2 overnight

 

[Red October]

Vinegar is quite useless, and 17-60ppm is soft water. If you are on the low end of that, it's not hard enough to offer good buffering, and in coco, that's even more of a problem. Are you loading up with maybe 2ml/L calmag?

Thanks man, this is a whole aspect I haven't gotten up to speed on, I've only added calmag twice during these plants whole growth cycle, 'm not consistently adding each week. I've been watching the plants to indicate something is wrong so I can approach each issue directly but they've looked good the whole time so far, here's a fan leaf I just plucked off

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[Red October]

Don’t use vinegar in coco, use phosphoric acid, your ph will be more stable …if you have an air line in (which you should have) then that’ll raise it a point or 2 overnight

should I leave the ph down stuff out and rather use the phosphoric acid? I'm not using an air stone but I do have a pump in the tank to keep the water circulating, I figured it was just meant to keep algae growth diminished.

 

[Bush Dr]

Make up your nutrients as directed and then use phosphoric acid to get it to 6.1-6.2

Raising the dissolved oxygen level in the rez is always worthwhile …. Use Calmag every time you change your rez

 

[Red October]

Thanks again man, I've been waiting the whole time for the plants to show me some deficiency or unhappiness but they just keep trooping along, I went with the water pump because I wanted it to be quieter than using an airpump and figured because the water is circulating that new water would be exposed to the oxygen level, but I'm about to setup a second reservoir and will use an airstone and monitor the differences

 

[superjet]

Vinegar is quite useless, and 17-60ppm is soft water. If you are on the low end of that, it's not hard enough to offer good buffering, and in coco, that's even more of a problem. Are you loading up with maybe 2ml/L calmag?

Red October said 17-60 mg/l not 17-60 ppm check your PPMs it's higher than 60

 

[f-e]

superjet
Most water companies will use mg/l and PPM interchangeably. Which is true, if the substances involved have the same specific gravity. However, calcium carbonate has an SG of almost 3, so 60mg/L won't become 60ppm as it's smaller. PPM is volumetric, not weight. So it's more like 20ppm.

I hope I'm not too stoned for this.

 

[Kyomaoin]

To solve the problem it is necessary to lower the concentration of calcium carbonate and calcium bicarbonate in the water before feeding, to do this it is necessary to add vinegar (or strong acid such as nitic or phosphoric) to the water and reach ph 5, 5 remember the amount added then wait 24 hours test the ph level again then add more vinegar to reach ph 5.5, each time you do this you can see the ph of the water go up less and more slowly. the optimal point is to obtain a water with enough buffering of carbonates and bicarbonates to slow down the oscillation of the pH of the solution but not too much to keep the pH in the interval between one feeding and another. when the optimum is reached you can add all vinegar or an acid at once and after 24 hour you have perfect water ready.

it's simple:
less acid in solution more carbonate and bicarbonate less ec more ph climb up more stability to ph swing

more acid in solution less carbonate and bicarbonate more ec less ph climb up but less stability to ph swing when solution interact with the plant and sub

sorry for my english

 

[Red October]

To solve the problem it is necessary to lower the concentration of calcium carbonate and calcium bicarbonate in the water before feeding, to do this it is necessary to add vinegar (or strong acid such as nitic or phosphoric) to the water and reach ph 5, 5 remember the amount added then wait 24 hours test the ph level again then add more vinegar to reach ph 5.5, each time you do this you can see the ph of the water go up less and more slowly. the optimal point is to obtain a water with enough buffering of carbonates and bicarbonates to slow down the oscillation of the pH of the solution but not too much to keep the pH in the interval between one feeding and another. when the optimum is reached you can add all vinegar or an acid at once and after 24 hour you have perfect water ready.

it's simple:
less acid in solution more carbonate and bicarbonate less ec more ph climb up more stability to ph swing

more acid in solution less carbonate and bicarbonate more ec less ph climb up but less stability to ph swing when solution interact with the plant and sub

sorry for my english

Many thanks, I'm going to take some time to read up on this as we do have lime added to out water and this could very well be it. I noticed the water in my reservoir has gotten smelly this week so now I'm worried I have root rot starting somewhere but all the plants look extremely healthy. This is all a learning curve for me but I was expecting the plants to show some level of unhappiness but they just aren't.

 

[gaiusmarius]

in general i would advise against mixing coco with perlit. it literally just makes everything harder to keep dialled in. have seen this countless times over the years. a soil mix with coco and perlit is easy, but coco and perlit mixes are delicate mediums to grow in. coco is already perfect as it is. you can get really great results just using your basic nutrients, no worries about cal mag, ph, or beneficials.

 

[Red October]

in general i would advise against mixing coco with perlit. it literally just makes everything harder to keep dialled in. have seen this countless times over the years. a soil mix with coco and perlit is easy, but coco and perlit mixes are delicate mediums to grow in. coco is already perfect as it is. you can get really great results just using your basic nutrients, no worries about cal mag, ph, or beneficials.

Should I get the type that has some of the larger husk material in or the more homogeneous fine type? There's so much conflicting info everywhere it makes things very difficult to read up on this type of stuff, if the pure Coco gives a more consistent environment for the roots then I am down with that!

 

[f-e]

I'm not sure there is a place for coco 'peat' types, now HIDs have gone. The professional choice has always been for more air, which leads towards automated irrigation. The extra space in the pot and more frequent irrigations, mean smaller pots or slabs can be used. The number of pro grows using pure coco is quite low now, and which type isn't published.

If you use the peat types under LED, you will need to use half the irrigation water before watering again. The wet dry cycle, needed to get some air in there. If you use a better draining coco, you can do the multiple irrigation's per day, as it won't get too wet. With HID you could easily dry pure coco peat to reasonable levels quite quickly. Under LEDs, plants do drink as much, but not when waterlogged. I think the accelerated growth rates are stunted by the lack of oxygen at the root, and it's those higher growth rates that shift the water with an LED grow, Not the higher heat like an HID grow.

I'm just forming some of these opinions recently, and opinions are all they are. Nothing is night and day fact, in every situation. However the volume of test grows pointing to this is very considerable.

 

[gaiusmarius]

it worth going for high grade coco, ideally get something thats made to the standard of canna coco. meaning it should be steam cleaned as well as flushed of excess salts, with a nice low starting ec. but even if its not flushed you can flush till the return ec is nice and low, anything under 1.0 ec is good enough to get going. if you are not recirculating the water the flush isnt so important. my grow shop sells generic coco slabs with no name that are the same as the canna coco slabs but a bit cheaper.

 

[Red October]

I'll have to do an ec test on it but I am hoping they would treat it first. Many thanks Gaiusmaruis your input is appreciated.

 

[Ocean.grower]

you saved my life with so much information, thank you