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Reservoir Dogs

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
I've read several posts lately about the frequency of changing your reservoir. Some espouse the rule that a full res-change weekly is required. Some say every two weeks does the trick. I wonder if anyone has done an unbiased test to see which is best.

The way I look at it is this. There will always be unused nutes in the res when you empty it. If you had the proper test equipment to give you a breakdown, you could just top-up on the nutes that were low. Well the equipment is expensive and who can afford a lab to test samples.

I have been doing Salt Walter aquariums for 20+ years. I never change more than 50% of the water at any given time; there are several similarities to hydroponics (bacteria, build up of potentially harmful salts and substances etc...). And I guarantee some of the Marine Sea Life is much more sensitive to their environment than the plants we grow.

I also believe that just like the shampoo companies wash-rinse-repeat directions the nute companies want you to use more product more often.

Now I should say before I go on, that everything I say is based purely on my observation and opinion. If anyone has a scientific background, please chime in.

Here is my take on my reservoir. I am currently running a recirculating NFT system that has a total capacity of approximately 20 gallons (the pipe holds about 7 gallons and the res 13+).

- I do a partial change every two weeks, roughly 50% of the nutes are removed and replaced.
- I never do a complete change until the grow is complete.
- I have a top-up res that feeds R/O water to the system so that the volume remains constant.
- I monitor and adjust PPMs every 2-3 days (I don't obsess over the system).
- I DO NOT use H2O2 in the res. I have a very large micro-pore air stone. I don't want to kill off the beneficial nutes and fungus. (I use Great White and Hygrozyme)
- My res does not have any odors and there is no slimy build up or algae growth. The nutes are clean and clear and the bottom of the res has no build-up.
- I have a res chiller that keeps the temps at 68 deg.
- I tend to keep my ppm's below the recommended level (CES recommends 1400- 1600, I try to stay below 1200)
- My roots are very healthy and white, the plants are looking great (check my journal for the pics)
- Between the massive aeration and the nutes returning from the chiller (via pump) there is a lot of movement in the res and the nutes are in a constant recirc with the NFT. No chance for stagnation.

So, my question is, how often do you perform a res change? Please try to keep the discussion civil. I know that my schedule is "controversial" and will get a lot of "heated opinions".

What I am looking for is:
- How do you maintain your system
- Is it different for organic vs. chemical nutes
- Have you tried a different schedule
- Are you basing your decision on "that's the way they've always done it" or on your own observations

Please no bashing anyone's input. This is a place for learning and sharing information that may be applicable to other members. I know that everyone's setup is different and requires its own maintenance (if I didn't have a chiller and tons of aeration it would change my routine for example).
 

cryodude

New Member
Steve, off topic a tiny bit, how do you do the aeration of the res? do you have an air pump next to it, running a hose into the res? i am new and reading tons, hope you don't mind the silly question. thanks!
 

HeadMed

New Member
I change mine every 2 weeks. but have thought about what your doing. I hadnt thought about the fish tanks.... but now that you mention it that is how i was taught to care for a freshwater tanks as a kid. And mom always made it a point to mix old soil with new when transplanting....
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
Steve, off topic a tiny bit, how do you do the aeration of the res? do you have an air pump next to it, running a hose into the res? i am new and reading tons, hope you don't mind the silly question. thanks!

Cryodude,
I have a heavy duty air pump and a large micro-pore airstone. I'll take some pics in the morning and post them.

I change mine every 2 weeks. but have thought about what your doing. I hadnt thought about the fish tanks.... but now that you mention it that is how i was taught to care for a freshwater tanks as a kid. And mom always made it a point to mix old soil with new when transplanting....

I see a lot of similarities between aquaria and hydroponics. I don't have any scientific proof, so I am going off my experiences with the former. The main purpose of water changes was to reduce the build up of wastes and to clean detritus from the bottom, but always tried to keep half of the water in the tank for the nitrosomonas and nitrabacters. I am sure that many of the beneficial bacteria and fungi reside in the hydro system and doing a full change, clean and fill will reduce or eliminate their presence

I would like to do an aquaculture setup once I have enough space for the equipment, maybe raise some shrimp to go with the herbs, but that's another post.

Cheers,
Steve
 

HeadMed

New Member
[/QUOTE]

I would like to do an aquaculture setup once I have enough space for the equipment, maybe raise some shrimp to go with the herbs[/QUOTE]


Thats a killer idea... think i could raise shrimp my wife wasn;t allergic to? i hear its something to do with iodine.
 

cryodude

New Member
Thanks Steve. your grow is so awesome.. i want hopefully get similar results later this year but i have no exp with hydro at all. At least i can afford to get good equipment and set it up right.. then i just have the learning curve after that..

cryo
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
Thanks Steve. your grow is so awesome.. i want hopefully get similar results later this year but i have no exp with hydro at all. At least i can afford to get good equipment and set it up right.. then i just have the learning curve after that..

cryo

Cryo,
I had zero experience myself. I read a lot of the grow journals and did a ton of research on the internet to get a basic understanding of the process. There is a ton of information out there and I learn something new everyday. The key is to educate yourself, and before you take advice from anyone verify their recommendation with a simple Google search. I've seen too many people passing off bad information as the gospel and pointing new growers in the wrong direction (but all out of good intention).

Hydro is not as difficult as I thought it was going to be. Now it is just a matter of fine-tuning my system and process to get the best results.

Best of luck on your grow,
Steve
 

cryodude

New Member
Thanks, as i get closer to starting i may pick your brain a bit if you don't mind, and i can't wait to see how this grow you are on finishes out.

Continued success sir,

Cryo
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
Steve, off topic a tiny bit, how do you do the aeration of the res? do you have an air pump next to it, running a hose into the res? i am new and reading tons, hope you don't mind the silly question. thanks!

Cryo,
As promised, here are some pics of my aeration setup.

The air pump (that is 1/4 ID hose, not the typical 1/8in. lots of volume):
DSC_8590.JPG


An over view of the res, not sure if you can see all of the bubbles, but there are a lot of them:
DSC_8591.JPG


The micro-pore air-stone (about $40):
DSC_8592.JPG


A little pvc base I made that holds the air-stone off of the bottom of the res (reduces noise and allows more nute circulation). The "stand" also doubles as a level gauge, you can see the tick marks on the side--it lets me keep track of water use. But now that I have the float valve and top-up res, I don't need to check it, so it's just a stand for the air-stone:
DSC_8593.JPG


I am also considering feeding an airline to the supply side of the NFT recirc to add a little more air. The water pumps have a fitting that allows for the attachment of an airline. More air can't be a bad thing.

I think that a strong aeration system is the critical element to any hydroponics system and you should buy the best quality air pump and air stone your budget allows.
 

cryodude

New Member
Steve, yeah i see bubbles, tons of them, like 20 muskrats under there having a burping contest. I'd imagine that the pump in the res for the water circulation is at least 1/4 horse also? how much gpm to keep 4" pvc full, there must be some smaller restriction at the return end to aid in filling the pipe, or is there something i am missing? so that once full, the return is about the same as the pump pushing in?? I need to go back into your journal and see if there are some shots and info on this. Does the re-circ run all night after the lights are off or shut down also after llights out and come back on before lights on?

Thanks,

Cryo
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
Cryro,
I have two 290gph pumps in the res, not sure of the hp on them, but sure its no where near 1/4 hp. One is attached to the chiller (the chiller is 1/10 hp and is half the size of the res) and keeps the res circulating so that the nutes are constantly moving and getting aeration. The second 290 gph is attached the the 4 inch NFT system and pumps the nutes through the 4 inch pipe. It feeds the NFT through a 1 inch pipe (the pump is attached via a length of 5/8 hose and a barbed fitting). The return to the res is via 4 inch pipe with a downspout adapter. You should be able to see both in the grow journal (if you need better pics let me know and I will post them for you).

Both pumps run 24 hrs, I want to maintain a constant temp and aeration level for the res and the nutes so that the roots and beneficial bacteria and fungi are all happy.

Hope that answers the question, if not let me know.

Cheers,
Steve
 

cryodude

New Member
it sure does, thanks Steve. Once I get enough posts up I'm going to PM you on this thing! This has been fascinating to watch , and i've greatly enjoyed interacting on your journal thread.
 

Caber1

New Member
My input on reservoir changes would be that everyone is going to have to make their own decision based on reservoir size to amount of plants being fed and also what my "parts per million" monitor is telling me about whether the plants are taking water or nutrients.
I will say that when I get lazy sometimes it is amazing how healthy my plants will stay with little or no help from me.

Steve can you tell me how loud that air pump is that you have in the photo. I see you have it suspended to dampen the vibration.
I'm looking for something to aerate a 150 gallon reservoir and I'm of course looking for a good price and output.
What output/size/wattage is yours? Also did you find it at a pond store or a hydro outlet?
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
My input on reservoir changes would be that everyone is going to have to make their own decision based on reservoir size to amount of plants being fed and also what my "parts per million" monitor is telling me about whether the plants are taking water or nutrients.
I will say that when I get lazy sometimes it is amazing how healthy my plants will stay with little or no help from me.

Steve can you tell me how loud that air pump is that you have in the photo. I see you have it suspended to dampen the vibration.
I'm looking for something to aerate a 150 gallon reservoir and I'm of course looking for a good price and output.
What output/size/wattage is yours? Also did you find it at a pond store or a hydro outlet?

Caber1,
I'm using a Sunleaves Durapump 530, it is an 18 watt unit that puts out 600 gallons per hour of air. It is about the same noise level as my smaller airpump, where the noise really comes from is from the airstone, all of that air in the res makes some noise. That is one of the reasons I put it on a little stand made out of pvc, to keep it off of the bottom to reduce the vibrations.

For a 150 gal res, I would look at a larger pump and put 2 (or 3) of these micro pore stones in there. I would look at one of the Danner Pondmaster pumps, they look like they are built for heavy-duty applications.

Another thing I've considered is placing an air inlet into the return line from my chiller to aerate the nutes on their way back fro the chiller. Inline aeration is very popular in brewing (another hobby of mine) and could boost your ORP. I found my pump at the local Hydro store. The good thing about my local guy is that he will match any price I can find online, since they are all ordering from the same places. He'll even do custom orders and give em the best price possible--have to keep the local guys in business.

As far as changing the nutes in the res, sounds like we're on about the same page. I keep an eye on the pH and PPM (every few days, I'm not obsessive about it) and adjust as needed. I also keep an eye on the girls to see what they need, and so far, aside from a little tip-burn, they haven't complained.
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
In a pure aero setup there really isn't a need to aerate, there is enough surface area and contact with the air to do the job. It is a little over kill really. I've modified the setup a bit to be an NFT/aero hybrid, and that still has enough flow and surface area to not really need an air pump. I may take it out of the equation on the next grow to see how it performs (it will be quieter for sure).
 

StonerJ

New Member
I just run a 10 gal res w/8 gals of solution & a single plant. It has two air stones and a 1/2" tubing loop driven by a 260 gph pump thru a 1/10 hp chiller. Steady solution temps at 68. I change every 2 weeks during veg and every week during flowering. The chiller return is a few inches above the solution level so it also splashes returning solution into the res in addition to the 2 air sones running. I also run low nute levels, 5-600 ppm of Technaflora BC products. I add 50ml H2O2 every third day, 100 ml on a res change. I start with RO water and add the nutes which gives me a perfect pH damn near every time. I supplement Cal-Mag occasionally if the plant seems to need it. Roots are beige form the nutes (I run much higher in veg and get fast healthy dense growth) but very, very healthy.

It's easy to pump the old nutes out and empty the chill loop all with just a hand siphon pump, then refill from a spare res with the nute solution. Entire process takes about 20 mins & it's done. There is typically never more than 10-20 ppm of the old solution left in the res when I refill it so it has little impact on the nutes.

:thumb:
 
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