PH/PPM meters for DWC?

[wang]

So I'm just about ready to start my first grow, 2 5-gallon DWC buckets in a 7.2sq ft closet under 400W using RO water, a microbe tea and GH flora micro and bloom.

One of the last things on my list before I start the grow is to get a PH and PPM meter. Now, if things go well, I don't plan on staying in this closet for long, so I'm looking for something that will be able to handle expanding the grow so I won't have to throw it out when I'm done.

I was first looking at the cheap-o hand-held meters on ebay, like the Hanna primo, but am afraid that those won't last very long or won't give me accurate readings.

What do you guys suggest, say a limit of $150 for both meters combined (or a combo meter), but if there are quality options for cheaper I'd be very interested in those as well! I'd also like opinions about hand held meters vs probes.

 

[guest456mpy]

I've been using a Milwaukee SM802 for about 5 years and it only needs calibration (You DIY) for maintenance as long as you keep the probe tip wet. I just keep mine in a coffee mug of water and it's been accurate and durable.

'Bout that price.

 

[FreezerBoy]

At $150 combined, I'd spend $130 on a BlueLab EC Truncheon (hands down best EC meter around) and $5 on a test drop kit from the aquarium store.

Meters and pens cannot measure "PPM" or "TDS". All you can measure is EC. Do yourself and the hobby a favor and avoid so called "PPM" and "TDS" meters for the real thing, EC.

pH pens are little more than toys and a crapshoot at best. You pays your money and takes your chances. In general, Milwaukee sucks the least, followed by Oakton with Hanna scraping up the bottom of the barrel.

 

[jammie]

hey there wang- i've had the nutradip trimeter (ec,ph,temp) for 4-5 years and love it. i think they run about 150 on ebay. very durable, holds calibration

 

[ThePizzaMan]

yeah, do yourself the favor and skip the cheap pens all together...they are just a waste of your time. IF you were dead broke, I would say maybe...but with $150...you can get yourself something real nice

 

[marrdogg]

Oakton PH2 never had an issue with it. I just rinse the tip after each use no keeping it wet or storing in calibration solution. Every couple weeks calibrate it and it's good. Also only paid $60 for it. Milwaukee personally don't care for there calibration method didn't like it they have new ones but were always a pain in the ass, Peace!

 

[wang]

thanks for the recommendations!

I ended up ordering a Milwakee MW802 which is the new version of the SM802 it looks like for $120.

 

[wang]

So I just hooked up my pump, I have 2, a 4-port TopFin AIR 8000 that I was going to run both my 5-gallon buckets off of and a Whisper 30-60 that I was going to use to aerate my bennie tea.

The action the pump is giving me is getting me a little worried. There are a lot of bubbles, but theres not very much water movement. Its a 7W pump so I figured it should have the juice to power 2 res's with 3gal each. I'm using the ecoplus 4' flexible airstones. Is just small bubbles okay or am I looking for more?

 

[wang]

Just took a video of the bubbling action, sorry it's a phone camera.

Can anyone tell if that's good enough or not?

http://www.youtube.com/watch?v=9XFWHRbEoQw
[iframeb]9XFWHRbEoQw[/iframeb]
sorry, I know the quality sucks and its hard to tell.

edit: after watching some other videos I'm not quite as worried, this looks about right. Right now I have the 2 outputs from the pump going to a T-connector to the 4' flexible airstone for each bucket, would It be better to have 1 output for the flexible airstone then 1 output for another smaller airstone instead, or maybe an open line? (basically cut out the T connector and run another line in each bucket) It looks like the amount of small bubbles, are fine, I'm just worried it's not splashing enough to feed the roots

 

[marrdogg]

Personal opinion I would run each pot on it's own individual pump unless you have one big enough to supply air to two pots. Looking at the video you're going to need more aeration once roots getta going. You don't want pockets not receiving air. Peace!

 

[FreezerBoy]

I'd think the 8000 (170 gal) would do fine. I use the 3000 (smallest two outlet model, 40 gal) with my 2.5 gal bubbler and two 12 air bars. My water rolls like it's boiling. If you're not getting the air flow you like, I'd try another aerator.

Check the underside of your lid for wetness. If the lid's wet, then water has to be reaching the bottom of the net pot.

Air stones are more about stealth than anything else. Waterfalls employ no bubbles and are the most effective means of aeration. Problem is waterfalls are big and loud. Air stones are tiny and quiet. If you can "afford" the noise of big bubbles going BLORP... BLORP... BLORP you don't need a stone.

 

[wang]

Yea, I figured the 8000 would be good to power 2 buckets, it's rated at 10.67 LPM. I'm thinking maybe the airstones the guy at the hydro store sold me on aren't that great. I tested it using a 4" airstone and the 4' flexible diffuser, and it does look a little better, one of the 4' diffusers seems less effective than the other though

 

[wang]

So I ran a few tests. First of all as soon as I put my net pot in I realized my water level was too high before, so with that lowered things are looking a bit better.

I tested 3 scenarios, all of them using the same 2 outputs from the TopFin 8000 pump.

Scenario 1: 2 outputs to T-connector to 4' flexible air diffuser
With this setup, I have a pretty even distribution of generally small bubbles, but there are a lot of them. The bottom of the netpot gets pretty well covered in water droplets that range in size. I would characterize the water movement a little less than a rolling boil, but it definitely looks like it's boiling.

[iframeb]FccnxjyFqHY[/iframeb]

Scenario 2: 1 output to 4' flexible air diffuser, 1 output to 4" airstone
With this setup the small bubbles are smaller in number and power. The 4" airstone does add a nice "rolling boil" quality to the middle of the res, but the edges of the bucket don't have much movement. The bottom of the netpot seems to be covered in smaller water droplets than the previous scenario.

[iframeb]09LPq-P-BwA[/iframeb]


Scenario 3: each output has it's own open-ended line in the res
With this setup I get much more rapid water movement. Suprisingly, the bottom of the net pots were dry.

I think I'm going to keep with the T-connector to the 4' flexi for now, it seems to have covered the netpot the best, while keeping the best distribution of oxygen in the res. Thoughts?

I was planning on running 2" below the netpot which is what these tests were run at, but have been reading maybe 1" is optimal? With an empty net pot in the bucket should I see splashing above the bottom of the net pot?

This should be my final question before I start, my fan, lights and meter should be here by next monday, so keep an eye out for a grow journal!

 

[FreezerBoy]

Grow journal... oh noes. We've created a monster.

The reason for the air gap is the upper roots are airhogs. Transplant a seedling too low, it will stall for a week or so while it builds new air breathing roots towards the surface. Some non-mj plants are so hungry for air they build roots above ground. Point being, net pot and upper roots of mature plants need not be saturated. All they need is to be not bone dry for extended periods. Between bubbles bursting up, water dripping down from the inner lid and the relatively higher RH of the tubs interior, I can't imagine your pump letting you down. I do bi-weekly maintenance and generally allow the air gap to drop to 4-6 inches.

 

[wang]

Just planted my first plants Thursday!
https://www.icmag.com/ic/showthread.php?t=225346

 

[atomos]

i have a cheap hand held ppm meter and its works great!