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JimmyPage

Nute heater issue ... (but not really a pH one ????)

So decided to try and do things "by the book", and set up my DWC with the 100W aquarium heater (Theo ?).

 

AIUI the idea is to keep the nute temp around 20C - but not higher as it can encourage bacteria.

 

1st off, it seems the thermostat can't go lower than 22.

2nd off, checking Dr. google, it seems there's some discussions that the thermostat packs up rather a lot ?

3rd off, with thermostat set as low as possible, the nute temp is still reading 25 :( 

 

rather than buy a smaller heater, I've dug out a 24 hour segment timer (for some reason I have a lot spare :) ) and set it on/off for 24 hours. So basically turning 100W into 50W.

 

Happy to hear peeps thoughts ...

 

Concerning pH, I read the solution pH just now, but refuse to believe that a weak solution where the roots haven't even touched yet can be 8.0 ... especially as the reading was moving around. So I've cleaned the pen and will wait the 24 hours before recalibrating and retesting ....

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Posted (edited)

I wouldn't bother with the heater. 

the one you have is way too big. I use a 100w heater in my rdwc res, which has a total volume of around 160 litres.

 

If you arte in dwc the (presumable hps)  light will  heat it enough, and lower temperature of the water = higher dissolved oxygen rate, (a good thing) but you don't want to go below about 16 degrees, ideally 19 degrees

 

Whats the temp of the water without the jheater? that will give us a better idea

 

As for the ph reading. DO you know what the reading is out of the tap?

I would invest in a decent PH meter if the one you have isn't trustable, its not worth the risk.

 

 

 

 

 

 

Edited by badbillybob
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7 minutes ago, badbillybob said:

 

As for the ph reading. DO you know what the reading is out of the tap?

I would invest in a decent PH meter if the one you have isn't trustable, its not worth the risk.

 

A tad over 7.1 out of the tap.

 

It's a BlueLab pen - just over a year old :( 

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oh right, well  bluelab stuff is usually rock solid, but would srtill be worth the cost of some calibration fluid to be sure.

can you check the temps in the pot without the heater in there?

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OK, well daily check showed nute temo was still 25C - so I've turned the heater off completely. I'll what it is tomorrow.

 

After cleaning and calibrating the pH meter, it was reading 6.6. Tap water here reads at 6.8.

 

We have ridiculously soft water here, and pH has never been a problem. The only reason I got a pH meter was because I had a go at adding silicon last year, and (correct) advice was it would fuck up my pH. It did, and I can't say I noticed any difference in grow or smoke. So no silicon now.

 

(There was a thread on silicon just after I decided to try. I wished it had been posted before, as it would have steered me clear).

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OK, checked today. No heat being supplied and nute temperature is 22 !!!!! 

 

Which is a tad too high ?

 

pH seemed the same, but then the root has only just started to show from the bottom of the net pot.

 

Plant seems OK - a little delicate on the stalk. I've propped it up slightly.

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what are your ambient temps atm??

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2 hours ago, HVACman said:

what are your ambient temps atm??

 

Hitting 27 (35 at the top of the tent :( ) and water is 23 ... can't do more., but plant isn't so bad ... 2 weeks or so to chop (I hope)

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Mate, I would not even consider a heater unless it was negative outdoors. I’ve just found mine gathering dust. For a remote res, then ok, cos you don’t have any heat load from the lights. Remember they are in essence a xxxW heater.

 

1 Person in a room creates 30w of heat on average according to cibse. The heater pails into insignificance due to your heat load from your lamps at a min. Running it is nonsensical.

 

Every application is completely different so stop me if I’m wrong 

 

All the best mate

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Just now, HVACman said:

Mate, I would not even consider a heater unless it was negative outdoors. I’ve just found mine gathering dust. For a remote res, then ok, cos you don’t have any heat load from the lights. Remember they are in essence a xxxW heater.

 

1 Person in a room creates 30w of heat on average according to cibse. The heater pails into insignificance due to your heat load from your lamps at a min. Running it is nonsensical.

 

Every application is completely different so stop me if I’m wrong 

 

All the best mate

 

 

No sounds right.

 

Given that everything is at "room temp" them in a house ambient is unlikely to drop below 18 anyway. Add to that the fact that water can hold a lot of energy (so takes a while to lose it) and over a day, you probably don't need a heater (as I have discovered).

 

That said, I did have the tent in the garage, and some days it was struggling to get about zero .....

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See every situ throws a curveball.

 

All you would need to control that is an individual stat with a dip probe and put it through a contactor or some sort of relay to energise the coil (240v keeps it simple and eliminates transformers) an turn your heater on, your heater then needs to be turned up to a comfortable spot (bit of trial and error required) so as to gradually keep the temp rather than just heating it too quick.

 

I can can explain better via a drawing if required. It’s just basically a get out of jail

card should your stat break!!!

 

Peace.

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See every situ throws a curveball.

 

All you would need to control that is an individual stat with a dip probe and put it through a contactor or some sort of relay to energise the coil (240v keeps it simple and eliminates transformers) an turn your heater on, your heater then needs to be turned up to a comfortable spot (bit of trial and error required) so as to gradually keep the temp rather than just heating it too quick.

 

I can can explain better via a drawing if required. It’s just basically a get out of jail

card should your stat break!!!

 

Peace.

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PS if you are in Hydro you gotta remember that if you are pumping air into it, what temp is that air, then add the heat of compression (finger over a bike pump) an you got some warm air goin in their mate!!

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7 minutes ago, HVACman said:

PS if you are in Hydro you gotta remember that if you are pumping air into it, what temp is that air, then add the heat of compression (finger over a bike pump) an you got some warm air goin in their mate!!

 

Air will start at room temp, so could be slightly higher in the solution. But then the atomising effect of the bubbles would lose heat - I'm guessing it's evens overall ?

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Air Conditioning is your friend ! :smokin:

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