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).
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).
