Grow Mediums Cloudy water. Pathogen or something else?

[Imagine]

Hi all!

After my last adventure in dwc and chasing ph all the time I decided to give rdwc a go and so far hasn't been going as planned. The problem is cloudy / funky fish tank smell and ph that climbs as much as a point overnight.

System holds 20 gallons plus top off.

I filled and tested for leaks and rinsed well, refilled with clean tap water and added 4 cups of bleach, scrubbed with a new scrub brush and ran the system for a few hours. Drained and rinsed 3 more times and refilled with fresh tap and ran it four days while my seeds germed.

At that time my water was clear but the ph was around 8.3. Just before adding the sprouts to the hydroton, I added my 2 part Mega Crop and Epsom to the res and ph'd down to 6.3 (took a butt load of ph down to get it there).

Within 24 hours the water was cloudy and within 48 is was very cloudy and had a funky smell and the ph had bounced back up to the upper 7s.

I pulled the net pots out and drained and refilled and added H2o2 and ran that for a while and drained and rinsed and refilled with 1/2 RO and 1/2 store bought RO with minerals, added my MC and started over.
48 hours later and I have cloudy water again.

Sorry about the long post but I have to be missing something and it's driving me nuts. Thanks in advance!

 

[Bruce Campbell]

No DWC/RWDC experience, but speaking from aquarium experience:

Sounds like a bacterial bloom. It's a normal thing that any new closed aquatic system goes through as ecological conditions equilibrate. In aquariums, it happens with initial fills and/or large water changes as the fast-growing / primary anaerobic bacteria that are normally present in water are able to flourish and out-compete others at the very start. It's usually micronutrient-limited (vs. macro NPK), and eventually goes away after a week or so once other competing bacterial populations increase, certain micronutrients are used up, etc.

I.e., it's not from surface contamination in your system, and completely draining / re-filling usually means that you'll have to deal with a new bloom all over again. It sounds like the standard fix for RWDC is H2O2 addition, and some people will do that as part of their regular on-going regimen while others prefer to see if the system works through it on their own.

Your pH swings may be somewhat related, but could be a separate break-in issue. If it's taking a lot of pH down at the start, you probably have a lot of alkalinity / buffering in your initial water and very little once you reach the target pH. That means the pH can be very sensitive to small changes in chemical make-up and change quickly. I would just keep adding pH down each day and see if the pH eventually stabilizes.

 

[Imagine]

No DWC/RWDC experience, but speaking from aquarium experience:

Sounds like a bacterial bloom. It's a normal thing that any new closed aquatic system goes through as ecological conditions equilibrate. In aquariums, it happens with initial fills and/or large water changes as the fast-growing / primary anaerobic bacteria that are normally present in water are able to flourish and out-compete others at the very start. It's usually micronutrient-limited (vs. macro NPK), and eventually goes away after a week or so once other competing bacterial populations increase, certain micronutrients are used up, etc.

I.e., it's not from surface contamination in your system, and completely draining / re-filling usually means that you'll have to deal with a new bloom all over again. It sounds like the standard fix for RWDC is H2O2 addition, and some people will do that as part of their regular on-going regimen while others prefer to see if the system works through it on their own.

Your pH swings may be somewhat related, but could be a separate break-in issue. If it's taking a lot of pH down at the start, you probably have a lot of alkalinity / buffering in your initial water and very little once you reach the target pH. That means the pH can be very sensitive to small changes in chemical make-up and change quickly. I would just keep adding pH down each day and see if the pH eventually stabilizes.

Thanks KDawg makes sense. Don't really want to run a sterile system if I can help it so hopefully it will work though it. It's funny that the "bloom" happened after the addition of the neuts. Makes me wonder if the fertilizer is the food or contains the bacteria too.

 

[DCLXVI]

I think botanicare hydroguard comes heavily recommended from @Mañ'O'Green to keep DWC systems healthy.

 

[Imagine]

I think botanicare hydroguard comes heavily recommended from @Mañ'O'Green to keep DWC systems healthy.

True. I used it the last round with regular DWC and had zero root issues although my water temps were higher than they should have been.

 

[Mañ'O'Green]

What is the source and starting PPM of your water? If you are on municipal water you should be able to get a water quality report online. You may not need to use RO? Do you have adequate aeration in ALL tanks including your top-off tank?

Is that a chiller I see? does it have metal coils that come in contact with the nutrient solution? If so is the metal 100% stainless steel?

The system is not likely contaminated by any kind of living organism with the cleaning you have done but your household plumbing could be?

Lets start here then we can look at other problems.

 

[Imagine]

What is the source and starting PPM of your water? If you are on municipal water you should be able to get a water quality report online. You may not need to use RO? Do you have adequate aeration in ALL tanks including your top-off tank?

Is that a chiller I see? does it have metal coils that come in contact with the nutrient solution? If so is the metal 100% stainless steel?

The system is not likely contaminated by any kind of living organism with the cleaning you have done but your household plumbing could be?

Lets start here then we can look at other problems.

The source of the original fill was tap @ a ppm of 123. The second fill was RO to try and rule out waterborne issues from the plumbing.

Running dual air pumps to supply both grow sites and top off tank but not the res. That's an easy fix.

The chiller is an active aqua with titanium coils.

 

[Mañ'O'Green]

Titanium can be reactive to chlorine so the really strong bleach may have caused some oxidation which would be white? But i don't think this is the issue it would take a long exposure to do much oxidation. We are talking years not hours. The fishy smell leads me to some kind of anaerobic microbes. Are you using new air stones? New PH balanced Hydroton? What nutrients and addatives are you running?

By the way your tap water should be ok but is a little high in calcium? You might want to consider an RO system and blend your tap water down to 80 PPM.

HydroGuard should out-compete the microbes causing the smell but it would be better to chase down the source and eliminate it.

 

[Bruce Campbell]

Did you rinse or soak the hydroton or whatever media you're using before adding it?

The bacteria that cause the bloom need silica and are normally limited by it. In aquariums, you can get a spike in silica from new media, and it's usually recommended to rinse it thoroughly to remove smaller dust particles from shipping / handling - although there is still some leaching of silica at the start even if all the dust is removed.

Overall, I doubt the bacteria themselves are bad for your plants - just that they're eating up some N and P along with the Si, and possibly making your pH swings worse. Eventually they use up the excess Si and balance out to "non-bloom" levels.

 

[Imagine]

Titanium can be reactive to chlorine so the really strong bleach may have caused some oxidation which would be white? But i don't think this is the issue it would take a long exposure to do much oxidation. We are talking years not hours. The fishy smell leads me to some kind of anaerobic microbes. Are you using new air stones? New PH balanced Hydroton? What nutrients and addatives are you running?

By the way your tap water should be ok but is a little high in calcium? You might want to consider an RO system and blend your tap water down to 80 PPM.

HydroGuard should out-compete the microbes causing the smell but it would be better to chase down the source and eliminate it.

Air stones were from the last grow but were scrubbed in a mild bleach solution and well rinsed.

The hydroton is new but was soaked and rinsed.

Using Mega Crop 2 part With a bit of Epsom salt and Hydroguard currently but will be adding liquid humic, kelp, amino acid, omina, silica and yucca next week. Modeling my feed schedule after yours.