problem with plants growing under 250w

[ktm250]

I have had the seedlings in the first two pics growing from seed for 4 weeks and 5 days now and they are growing soooo slow and i have no idea why.The biggest one is just over an inch high and the other is about an inch.Im growing in a growlush growtent purchased from ozponics on ebay and i have one 250watt hps and one 250watt mh and one 48watt cfl and one 28watt cfl.Also i have 2 X 120mm sunon fans in there for inlet and outlet.They are growing in coco/perlite and i am using 1/4 strength fert and running on 18/6 light times with a timer.

 

When i first put them in the tent i was was running lights on from 5am untill 11pm but the temp was dropping to between 10 and 15degrees through the night which was too cold so i changed the lights (on) time to lights on at 6pm until 12pm and it keeps the temp in between 23 and 28.I have been feeding them 1/4 strength fert for 3 weeks now once a week.The last time i gave them nutes they went from yellow to green but are still growing very very slow.

 

I dont think im over watering because i only water them about once every 4 days when it feels dry an inch or so from the top of the medium.I have a cheap ass ph tester,the green one with the gold and silver prongs and it measures ph,wetness and light.It is about 2 years old and might be usless now cause even after i ave just watered it says its dry and the ph readings for all my coco/perlite medium is over 8ph.I have bought a new one,just waiting for it to arrive in the mail.

 

I was using tap water but have been using natural spring water for over aweek now and i just watered them with rain water last night.

 

The two seedlings in the 3rd and forth pics are 13 days old from seed and are not growing that fast either but they look healthy but just growing way to slow.Can anyone point out what im doing wrong as im trying to do everything correctly since i have grown in a growbox in the past with the same results and just gave up and grew outdoors instead.I have read the problems that some people have had with there growtent releasing fumes and killing their plants but they were like this before i put them in the growtent and the fume smell went away the second day it was set up.I was using the greendream fert for the fist two weeks and now am using the hypergrow.I am also using homemade co2 with i cup of sugar to one teaspoon of active yeast and water.

Edited July 3, 2009 by ktm250

[ktm250]

more pics.

[ktm250]

I also have snow peas and cucumber and cherry tomatoe plants growing in there but they are all growing fine,but not my mg`s.

[Cyclops]

Put the nutrients up to full strength .... 1/4 is not going to cut it.

[Girus]

Dont care for your plants so much, fertilising in this early stage should be experimental, until you get the right mix.

Usually you would start fertilising about 2 to 3 weeks old depending on the stage of growth. Too much nutrients and it will result in a build up of salts in your medium and restrict the plant from absorbing the nutrients you gave it making the plant look like it is nutrient deprived. This depends greatly on whether you added pre nutrients to your medium before you had sown the seeds, if the medium has no pre nutrients its best to give them the nutrients, small doses at a time then build up to bigger amounts.

I dont think the lights you have would be a problem but theres no need to have that kind of range of different lights going. Fluros for germination are sufficient and give the seedlings slow growing time but a chance to grow a good root system before upgrading to higher wattage globes.

Heat is also a factor in early development. Your temperaure seems to be ok and even know getting 12 degrees or under is a little bit of a shock to your plants it shouldnt kill them but it will stunt their growth a little.

Watering is a huge factor for novice growers and experience will come with time, this depends greatly on your medium, if its wel draining or if it holds to much moisture. Your medium should be well draining and if everything is well usually you would water every 2-3 days. Testing this with your moisture meter and make sure its in the red before watering again (not in the first few inches but lower)

Edited July 3, 2009 by Girus

[ktm250]

I`d like to use more nutes CYCLOPS but from the research that i have done and thats alot,people say only to use 1/4 to half strength for seedlings of what the nutes bottle tells you to use.Even if i were not using nutes at all shouldnt they be growing faster than this?I have grown outdoors with no nutes heaps of times and they grow faster than this.And growing under lights is spose to be faster than outdoors. Edited July 3, 2009 by ktm250

[Cyclops]

I have grown outdoors with no nutes heaps of times and they grow faster than this. And growing under lights is spose to be faster than outdoors.

There are nutes in the soil, growing in a mix of coco/perlite there are no nutes at all so you have to add them, 1/4 and 1/2 strength is just going to starve them.

I have always used full strength from day one and never had a problem.

 

You need a conductivity meter to see exactly what the strength is.

 

Forget about the PH, it's not an issue unless you added ph down or up .... if so that could be the problem.

 

Over watering could be an issue but from what you said that should be fine.

 

Pull one out and have a look at the root system, are they all white and strong or a brownish colour and whimpish..

 

Last option, pull them out and place them in pots with loose soil/potting mix and see if they take off.

Edited July 3, 2009 by Cyclops

[jimbojones5678]

Cyclops you have your head up your ass telling him to use full strength nutes on baby plants like that

 

Stick with the feed strength you are using ktm250, you can slowly increase strength as they get larger and hungrier

 

It is probably your temps at this time of year that is causing the slow growth, I have exactly the same problem with a grow I'm doing right now

Because the root zone temps and the air temps are not ideal atm growth will be slowed and nute uptake will also be slow

 

13 days is still really young - just be patient

 

Jimbo

[Bazza]

here here jimbo

[Cyclops]

Cyclops you have your head up your ass telling him to use full strength nutes on baby plants like that

Jimbo

 

Nice reply Jimbo ..... I have been growing since 197? .... I know what I am talking about.