Help please. Plants are getting worse. (5 weeks into flower)

[Buddernugs]

The biggest thing is finding one that calibrates at 4.0-7.0-10.0 ….not 6.98 or some weird shit like that…..yours might calibrate at the weird number that could be a thing as well why it’s so off after calibration

 

[CheGueVapo]

Lights: 4x 2700k 13w EcoSmart Bulbs (1500 lumens each)

So it's just 6000lux with 52 Watts electrical power.
113lm/W.... "ECOSmart"

Even the Thrives are better

Watering every 2nd day.

This looks like typical beginner problem, overwatering without having the lights requiring it.
The roots rott that way.

I feel like an idiot.

I don't know anyone who NOT made this mistake at least once at the beginning of gaining experience. It's normal.

Check the weight of your pots when they are empty..... remember that. Water the hole pot completely with a little drain. and not water before they are closing to be empty, when it is not neccessary.

Are you actually using the function of auto-watering that the hempy bucket features, or why you water it at all?

Your roots need air, need the oxygene.... a constantly too wet soil kills the roots. They cant drink if you drown them every second day, while they still have enough water in the pots... plus getting water from the hempy-bucket supply pipe... thats a little lot water for only 6000lux, dont you think?

 

[Buddernugs]

Shit man lol when I first started I was useing cfls lol like I would have I shit you not….. 15+ cfls on one plant that I fed with cat shit and my morning piss lol…..cring….. thinking I was fucking Pablo Escobar daddy dingdong king fuckin dingaling….. not I look back and tel myself….WOW DUDE….I WAS A fucking tool…..a fucking try hard lol hahahahahha…..mega cring……. We all started their don’t stress it homie

 

[CheGueVapo]

I fed with cat shit and my morning piss lol

Well, humans waste is kinda toxic... the food our pets usually get from the industry isnt the best either, thanks god they dont have that long lifetime... but it could be longer with better food, thats why some cook high standard food for their pets themselfes. Usually the stuff that our pets food the industrial convenience types are made from is that stuff that not fits certain contaminant criteria for humans ;/ Like the fat fish from the baltic sea... humans should not eat that that often, they make a lot of pet-food from it... they dont mind if it the dioxines turn out cancer after 20 years... with their 10-15 years and we dont care either, cancer? euthanize! thats reality. What should we do, throw it away, back to the sea xD, one idea would be to not to catch it in the first place and not pollute our environment that hard, but thats against economic interests of course. In fact your morning piss and your cat shit contains a lot of stuff that are not inside a good cow shit and piss from a farmer. Its definetly not the same. You have microplastics in your piss, did you know that?

The point is, we humans and our pets are doing the most effort to flush all that shit out as good as possible with our kidneys or deconstruct them with the liver..... thats why you dont feed them (our piss/shit), or you might smoke them toxins/contaminants in it.

Im not considered about piss or shit... dont mind smoking "that"...lol... but im very considered about the "shit" that may be "IN" the shit. Does that sounds correct?

 

[Three Berries]

I have the pH strips, three kinds, and two soil probe pH testers and don't trust them. The strips are old and the probes just never match with anything. So what do you do?

One thing I see myself not doing is watering to runoff. My flowering plants are in 2 gallon pots and going though a good 1/2 gallon a day with a gallon every three or so. But this was just maintain moisture somewhat, no rinsing of accumulated nutes. My newer pots are 3.5 gallon and have a longer watering interval. FWIW the last grow was the 3.5 gal and there was plenty of room for roots, no circling the drain like the 2 gal ones with 3'-4' plants. It was a rushed end times for those ladies due to time constraints. never enough tents and lights I guess.

But the last two days I have been watering to run off, over a gallon each. Yesterday's was a good drenching with some 6.5 in and 5.5 out. So it appears I'm still adding too many nutes to be getting enough accumulation to be getting the pH that low? I use MG BloomBuster dry at the indoor rate, 1/2 teaspoon with a pinch of epsom salt pH balanced to 6.5-7.0, water is a gallon of rain water to a cup of well water.

Neither plant is looking stressed so I just need to be watering more when I do.

 

[Three Berries]

My current veg grow the one first out of the box and rooted, up and all suddenly started yellowing, quickly progressed to the first leaves. I was panicking. It turned out to be too dry due to being in a peat pot and I was checking the big pot. So it came out of it in a couple of days. But I stuck another seed in the pot next to it. It sprouted up today and I dug it up, basically down to the single tap root and a bit of soil. Put it in a 4" pot of recycled soil. It will be my experiment to see if I can get it to catch up.

Here it is next to it's bigger sister that got chewed up by the cat yesterday....

 

[LeastExpectedGrower]

What's your experience with decalibration of the meter you're using? How often do you think you would have to calibrate it before it becomes too inaccurate? I've heard that some meters stay accurate for quite long, but have no experience; not going to spend $100+ just to try.

I do not want to buy a meter if I have to babysit it beyond some acceptable point. Having to recalibrate before every use would be too much hassle for me, in that case it's easier to just use a test kit.

I calibrate mine every week and a half to two weeks, but I'm only watering/feeding twice a week...it's one of those cheap yellow ones. If the bulb dries out, it'll definitely be off (if functional at all). I generally know where the starting point of my tap (well) water is so if I pull from one of my jugs and find it nowhere near it's 6.9-7.1 range, I know to recalibrate it. Recalibration is quick once you do it a few times. I bought a kit with three bottles of solution and have a few little ramekins that I use to calibrate. I learned water in the cap, pen in the storage box, storage box wrapped tightly in a ziploc bag takes care of keeping it wet.

 

[Pawtz]

Where your tap EC starts at? Too much calcium may lead to potassium defficiency. I know shit about calcium ascorbate so hopefully you know what you are doing.

Not sure about my ec, but my ppm meter reads 122 cold and 186 hot.
Calcium ascorbate has around 10% of elemental calcium by mass. So it equals to around 10mg of calcium per gal of what they're getting.
-----

@Buddernugs His pH meter is completely decalibrated, it shows ~7.5 when the test kit shows ~6
Probably what was given to the plants was way too acidic, because when the meter would show 6 the water would probably be around 5 or lower.

Here's some more readings.
I pulled the chart from the internet. It's not from general hydroponics, but it looks on par given the other color representations that I've seen.

same picture as above(just on imgur):

http://imgur.com/a/WQh60ph

My pen seems off in some instances and not in others.
Does the 5.8 look legit? I know it might be hard to tell from the lighting. My phone camera seems to have bad color rendering, but the pics look on point from what I see with my eye in these instances. I tested multiple light sources and it looks the same.
-----

You should get a 7.0 test solution and adjust the meter to that before using every time. Then store the meter with a bit of that solution in the cap for the bottom.

Without calibrating it to a standard testing different solutions is a no win.

I want to, but doesn't that stuff have a shelf life of around 3 months after opened (the entire bottle)?
I'm fine with calibrating each week and leaving it in a 7.0 or etc solution to see if the pen goes -/+ over time.

And going by color, not everyone sees color the same.

That's why I would rather use a pen. There's a lot more nitpicking for me with the drops unless I have a pen to accurately test the level to determine how much ph -/+ to use and the color that results. I can't even tell a .5 -/+ difference. 5.6 would look the same as 5.8 to me.
-----

That is not a problem with test kits, however, because the bottle should show a color very close to the color in the vial. That does not seem to be true for the GH bottle, their printing for 6.5 is way off.

Their 6.5 reading is laughable as hell. I get more of a piss green. I hope they fired whoever thought that label up.
-----

This looks like typical beginner problem, overwatering without having the lights requiring it.
The roots rott that way.

Check the weight of your pots when they are empty..... remember that. Water the hole pot completely with a little drain. and not water before they are closing to be empty, when it is not neccessary.

I'm not familiar with root rot. I did look at some pictures and nothing looked similar to what I'm experiencing. I will dig more into that though and try to find some late stage pictures. Hopefully it's not that as I'm only testing the pH right now.

One of the reasons to lead me believe it might not be that is that they're all experiencing the same thing and it all came around the same time. However, they all are in the same medium (same coco/perlite, but smaller plant may have a bit less perlite), eat the same nutrients (smaller plant is watered slightly less), and are in the same environment. Seems the feeding solution might be the origin just from that alone? I only water the 2 bigger plants every 2 or so days just recently (since week 4 (little over 1 week ago)). They used to go around 3-4 days until watered, but I read that more frequent waterings were done for pots around 1gal. The smaller plant gets a bath around every 3 days and I'm going to roll back on that since you mention this (they're also much smaller than the others (1 week veg compared their 4 weeks)) and keep a closer eye on it's weight (as well as the others).

I lifted my plants before their last 2 feedings and they were very light in weight compared to after watering. That's during me watering every 2nd day. I have about 2" from the bottom where the drain is.

Are you actually using the function of auto-watering that the hempy bucket features, or why you water it at all?

Your roots need air, need the oxygene.... a constantly too wet soil kills the roots. They cant drink if you drown them every second day, while they still have enough water in the pots... plus getting water from the hempy-bucket supply pipe... thats a little lot water for only 6000lux, dont you think?

I know what auto-watering is, but not as a feature of a hempy bucket. What is that? Going to revise a lot of stuff in my next grow. May even ditch the hempy for something more air friendly.

I did a grow a year back and most things went fine with even less output in wattage (around 35-40w sqft). I was under the impression that the amount bulbs I was using (in this grow) was too powerful because I thought (at the time at least) that I was getting light burn. The same browning occured, along with leaf shape, but I got no bleaching at the bud sites. Now it's all looking like it's pH related as it's happening to the other plants.
-----
Here is how things were since late August till today.


same picture as above(just on imgur):

http://imgur.com/a/wucWpRC

 

[Bukvičák]

Not sure about my ec, but my ppm meter reads 122 cold and 186 hot.
Calcium ascorbate has around 10% of elemental calcium by mass. So it equals to around 10mg of calcium per gal of what they're getting.
-----


Here's some more readings.
I pulled the chart from the internet. It's not from general hydroponics, but it looks on par given the other color representations that I've seen.
View attachment 5002680
same picture as above(just on imgur):

http://imgur.com/a/WQh60ph

My pen seems off in some instances and not in others.
Does the 5.8 look legit? I know it might be hard to tell from the lighting. My phone camera seems to have bad color rendering, but the pics look on point from what I see with my eye in these instances. I tested multiple light sources and it looks the same.
-----


I want to, but doesn't that stuff have a shelf life of around 3 months after opened (the entire bottle)?
I'm fine with calibrating each week and leaving it in a 7.0 or etc solution to see if the pen goes -/+ over time.



That's why I would rather use a pen. There's a lot more nitpicking for me with the drops unless I have a pen to accurately test the level to determine how much ph -/+ to use and the color that results. I can't even tell a .5 -/+ difference. 5.6 would look the same as 5.8 to me.
-----


Their 6.5 reading is laughable as hell. I get more of a piss green. I hope they fired whoever thought that label up.
-----


I'm not familiar with root rot. I did look at some pictures and nothing looked similar to what I'm experiencing. I will dig more into that though and try to find some late stage pictures. Hopefully it's not that as I'm only testing the pH right now.

One of the reasons to lead me believe it might not be that is that they're all experiencing the same thing and it all came around the same time. However, they all are in the same medium (same coco/perlite, but smaller plant may have a bit less perlite), eat the same nutrients (smaller plant is watered slightly less), and are in the same environment. Seems the feeding solution might be the origin just from that alone? I only water the 2 bigger plants every 2 or so days just recently (since week 4 (little over 1 week ago)). They used to go around 3-4 days until watered, but I read that more frequent waterings were done for pots around 1gal. The smaller plant gets a bath around every 3 days and I'm going to roll back on that since you mention this (they're also much smaller than the others (1 week veg compared their 4 weeks)) and keep a closer eye on it's weight (as well as the others).

I lifted my plants before their last 2 feedings and they were very light in weight compared to after watering. That's during me watering every 2nd day. I have about 2" from the bottom where the drain is.



I know what auto-watering is, but not as a feature of a hempy bucket. What is that? Going to revise a lot of stuff in my next grow. May even ditch the hempy for something more air friendly.

I did a grow a year back and most things went fine with even less output in wattage (around 35-40w sqft). I was under the impression that the amount bulbs I was using (in this grow) was too powerful because I thought (at the time at least) that I was getting light burn. The same browning occured, along with leaf shape, but I got no bleaching at the bud sites. Now it's all looking like it's pH related as it's happening to the other plants.
-----
Here is how things were since late August till today.

View attachment 5002703
same picture as above(just on imgur):

http://imgur.com/a/wucWpRC

I would do this: quit adding vitamine C, take your tap (if you are aware of chlorine let it sit for a day but it wont help anyway) mix your base nutrients in it (K:Ca:Mg 4:2:1) around 1,1EC, be carefull of too much nitrogen and measure its pH by drops. I did it like this, fill your cap till 2cm, add drops, shake and put it on the white paper. Look at it from the top and the colour of the bottom is your pH. Colour 5,5-6,5 range your are fine do not mess with it and feed untill you get same EC runoff. You may need a lot of water. Than buy a legit pH pen and start to treat it like coco. GL!

 

[lusidghost]

So it's just 6000lux with 52 Watts electrical power.
113lm/W.... "ECOSmart"

Even the Thrives are better


This looks like typical beginner problem, overwatering without having the lights requiring it.
The roots rott that way.

I second this. I had a few plants that got overwatered while I was trying to tune in Blumats this past grow. I was seeing runoff in the flood tray, but I was having a hard time figuring out where it was coming from until I saw mold on the coco. Those plants took a hit and the rest thrived.

 

[CheGueVapo]

lifted my plants before their last 2 feedings and they were very light in weight compared to after watering.

Oh than never mind my assumption. Thats correct way of doing, so the roots should be OK. Just sounded in the hempy buckets plus watering so oftern, like potentially you were drowning them.

take your tap

Your tap contains Ca/Mg/Limes,....

(K:Ca:Mg 4:2:1) around 1,1EC

1,1 EC is 550ppm (500scale).. that 4:2:1 then you added:
around 80ppm Mg.... 160ppm Ca.... 320 ppm K.
Thats stabil, but not nice Could be nice for DWC .... but only when the have defiencies Overkill for soil!

They never need that much Lime, this high EC...not even yet N, P in, only K HECK?

 

[CheGueVapo]

I got a bluelab EC/PH-Combo-Meter for around a decade now.

The PH is replaceable. Needed two replacemnt probes in the decade... should have cleaned them better with organic, the microbes get IN
Thers a display indicator when PH-calibration got lost, so I recalibrate it then with 4.0 and 7.0 calibration solutions.
The good thing i noticed is that it looses the "calibration indicators" rarely with good batteries, and when it does lose it and i recalibrate it, it's simply just correct still... showing the exact right values for the test-solutions, re-applying the display cal-indicators... so I know even when the calibration indicator is lost, still i have correct values, I recalibrate it of course still and then Im fine for another HALF a year. I use always fresh new opened calibration solution so Im absolutely sure it is simply accurate and long term stable! I have test strips for cross checking, thats enough never dealt this color liquids. Dont have any reason to!

I calibrate mine every week and a half to two weeks,

Well, .... Then it seems to be accurate every week, or half a week, or every two weeks :=) Good short term accuracy

 

[oill]

I feel like an idiot. Close to 5 weeks into flower for my indoor grow. Watering every 2nd day.
Light Cycle: 12/12
Lights: 4x 2700k 13w EcoSmart Bulbs (1500 lumens each)
Medium: Around 70% Coco & 30% Perlite w/ the entire bottom layer being perlite to where the drainage is (it's a hempy bucket)
Nutrients: Tap water (+ around 100mg of calcium ascorbate to neutralize chlorine/ETC), 3g Megacrop, + 1.5g of Bud Explosion(0-26-37 pk booster) + pH down to get it to 6.2.
PH: 6.2
TEMP/HUMIDITY: 77-82F / 50-65% (around 50-60% during the day and jumps to 65% @ lights out). I am planning on adding a dehumidifier during the last few weeks because that's when I heard of people dropping the humidity real low.

The leaves are also not yellowing at all and going straight to brown. So I didn't think it was nute burn. The nutrients seem on par with what I see a lot of others getting away with (not completely ruling it out though). I just upped the "Bud Explosion(0-26-37 pk booster)" to 1.5g for the last 4 days because someone elsewhere said it was potassium deficiency, but I'm thinking something else.

I suspected it was the lights being too close on my other plant, so I switch to only 4 lights instead of 6 to help that one plant. This was 2 weeks ago. I thought after going that it would all correct it self, but it's getting worse and it's affecting all my plants (even the two that are far away from the lights) now.

Thanks for any feedback.

View attachment 5001098View attachment 5001099

same pictures as above(just on imgur):

http://imgur.com/a/biiTn5D

Your ph is too high.... a bet your run off is way higher than 6.2. You need to feed at exactly 5.9 and you need to feed til run off every day otherwise you'll get this issue


Edit.... didn't read the whole post lol... bit late... but I was right!....

Keep feeding every day til run off to keep that ph down....

 

[CheGueVapo]

Your tap contains Ca/Mg/Limes,....
1,1 EC is 550ppm (500scale).. that 4:2:1 then you added:
around 80ppm Mg.... 160ppm Ca.... 320 ppm K.
Thats stabil, but not nice Could be nice for DWC .... but only when the have defiencies Overkill for soil!

Im sorry.... @Bukvičák @Pawtz
Im an idiot... thx @oill to remember me that this is "Around 70% Coco"....
I dont know shit.... but the Bluelab pen is still god. Sry guys byebye. Im no help here with my soil assumptions! Sry
I just wanted to say you need higher pH

 

[Bukvičák]

Oh than never mind my assumption. Thats correct way of doing, so the roots should be OK. Just sounded in the hempy buckets plus watering so oftern, like potentially you were drowning them.


Your tap contains Ca/Mg/Limes,....

1,1 EC is 550ppm (500scale).. that 4:2:1 then you added:
around 80ppm Mg.... 160ppm Ca.... 320 ppm K.
Thats stabil, but not nice Could be nice for DWC .... but only when the have defiencies Overkill for soil!

They never need that much Lime, this high EC...not even yet N, P in, only K HECK?

Some nutrients have Ca and Mg inside, some not. His tap is fine for coco, no need to add more elemental Ca. And yes you are right that 4:2:1 is Hydroponic ratio, where the potassium stays available when calcium levels are quite high not when you already have deficient plants. It might be just simple as guys say, in case that pH numbers are correct. Since I think he struggles to get right measurements, I look at the plant and not see any pH issues. But I am just a noobish hobby grower.

 

[CheGueVapo]

I look at the plant and not see any pH issues. But I am just a noobish hobby grower.

When i remember the complexity of the excess/defiencies images showing up the symptons and then recapituilate the complexity of what might be the cause of each, once you find out what it really is, you must find out the cause of it.... to me a lot of the symptom-pics looks the same, you find a lot of wrong examples in the internet, just the wrong one.... and the cervantes chart for example is not photo, it's drawn, wtf... you have only "describtions" and one need to look carefully for the details, like younger or older leafs showing the symptoms first... that alone makes a huge difference to determine. If you found out... still you don't know the cause.

Usually the cause of lack of water that caused the burnes, totally gets forgotten.... sometimes people try< to riddle aboutdefiencies or excesses or pH and drain... while they simply had run the pots out of water under excess light ... no wonder. There is nothing wrong.... just continue in that case, watch the water supply

Even for a professional grower with lots of experience having the plants straigth infront of them to inspect them under good light, (sun light)... thats not an easy task, find out what is the cause. It never gets really "easy", to say "oh thats easy its that 100%".... it's never that easy, except for yourself if you experience that often for your fgrow and already foudn out what to do There is wind burn, there is drought stress, when the water depletes the salanity spikes... who knows, sometimes many things mix up to the individual "damage appearance" and it's rare that you only experience one thing... usually one problems dont come alon alone... first you must KNOW everything details... they tell more than PICs about what could be wrong. Thats my experience.

The more info the beginners post when they want answer to a more difficult problem than ie insect infestations (those are the easiest, someone sees it, notices and done)... but anything else can be hardly difficult without more information about light, watering strategy, nutritions, whats the substrate medium, ventilation, temperatures, etcetera...

Remote inspecting them via only Pics over the Internet, without any information, while they are under artificial light is more harder, more like "Jeopardy" - having a complex answer, finding the question, lol - but on insane difficulty-level . Inspecting them with purple light for example is impossible..... you see fine purple pistils, but you dont seestructural damage of the chloroplasts-complexes like chlorosis beginning... you see them well with enough green light shining through from the bottom... with that you can see if there is damage or if that yellowing is just more xantophylls for example. Inspect always with white light and check leaves down-sight enlightend.

Another thing is that the cameras change their "whitepoint", they balance the white spectrum... what you see on a PIC is not the reality in color and no matterit's ultra high resoluted.... we cannot see the leafs of a pic like in reality.... we more see dust on it then anything else The cams cannnot "display" the transluceny that a high green lighted leaf can offer to inspect with the high green photon sensitive eye of the human.

 

[Bukvičák]

When i remember the complexity of the excess/defiencies images showing up the symptons and then recapituilate the complexity of what might be the cause of each, once you find out what it really is, you must find out the cause of it.... to me a lot of the symptom-pics looks the same, you find a lot of wrong examples in the internet, just the wrong one.... and the cervantes chart for example is not photo, it's drawn, wtf... you have only "describtions" and one need to look carefully for the details, like younger or older leafs showing the symptoms first... that alone makes a huge difference to determine. If you found out... still you don't know the cause.

Usually the cause of lack of water that caused the burnes, totally gets forgotten.... sometimes people try< to riddle aboutdefiencies or excesses or pH and drain... while they simply had run the pots out of water under excess light ... no wonder. There is nothing wrong.... just continue in that case, watch the water supply

Even for a professional grower with lots of experience having the plants straigth infront of them to inspect them under good light, (sun light)... thats not an easy task, find out what is the cause. It never gets really "easy", to say "oh thats easy its that 100%".... it's never that easy, except for yourself if you experience that often for your fgrow and already foudn out what to do There is wind burn, there is drought stress, when the water depletes the salanity spikes... who knows, sometimes many things mix up to the individual "damage appearance" and it's rare that you only experience one thing... usually one problems dont come alon alone... first you must KNOW everything details... they tell more than PICs about what could be wrong. Thats my experience.

The more info the beginners post when they want answer to a more difficult problem than ie insect infestations (those are the easiest, someone sees it, notices and done)... but anything else can be hardly difficult without more information about light, watering strategy, nutritions, whats the substrate medium, ventilation, temperatures, etcetera...

Remote inspecting them via only Pics over the Internet, without any information, while they are under artificial light is more harder, more like "Jeopardy" but on insane difficulty-level . Inspecting them with purple light for example is impossible..... you see fine purple pistols, but you dont seestructural damage of the chloroplasts-complexes like chloris beginning... you see them well with enough green light shining through from the bottom... with that you can see if there is damage or if that yellowing is just more xantophylls for example. Inspect always with white light and check leaves down-sight enlightend.

Cool…

 

[LeastExpectedGrower]

I got a bluelab EC/PH-Combo-Meter for around a decade now.
View attachment 5002730
The PH is replaceable. Needed two replacemnt probes in the decade... should have cleaned them better with organic, the microbes get IN
Thers a display indicator when PH-calibration got lost, so I recalibrate it then with 4.0 and 7.0 calibration solutions.
The good thing i noticed is that it looses the "calibration indicators" rarely with good batteries, and when it does lose it and i recalibrate it, it's simply just correct still... showing the exact right values for the test-solutions, re-applying the display cal-indicators... so I know even when the calibration indicator is lost, still i have correct values, I recalibrate it of course still and then Im fine for another HALF a year. I use always fresh new opened calibration solution so Im absolutely sure it is simply accurate and long term stable! I have test strips for cross checking, thats enough never dealt this color liquids. Dont have any reason to!




Well, .... Then it seems to be accurate every week, or half a week, or every two weeks :=) Good short term accuracy

I only feed/water every 4 days. My accuracy is fine.

 

[Tuda51]

How dry is your medium when you feed on the second day?

 

[ComputerSaysNo]

Does the 5.8 look legit? I know it might be hard to tell from the lighting.

I think the 5.8 is too high on the meter, going by the color of the fluid (at most 5.5 would be my guess).
All the pictures you've posted show a fluid that is going into the orange, and that would be below 6.0 already according to the chart.

There's no way around it, you'll have to get calibration solution and use that to get your meter back on track.

Also, this reference with photos of actual vials is great. It also shows you really do not need 2 drops per vial, it only makes the color slighly more intense.

For me, the "6.0 yellow" has always been very obvious to recognize.

Their 6.5 reading is laughable as hell. I get more of a piss green.

"Piss green" is actually a very good reference for 6.5

At the end of the day, how accurate do you have to be? If, say, 5.8-6.2 is good enough, that means you will have to get a clear "yellow" with not much orange or green in it. It's possible for me to recognize that, but for somebody with some form of color blindness it might be a problem. These people should not use test kits or test strips in any case, though.