RDWC Urgent Help, Temp caused Bacterial

  • Thread starter GrowDoggy
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Hey all, grow doggy here.
I need as much urgent advice from as many different people I can get, because in about 6 hours - At Most! - I will either fully drain and refill or make amendments based on my own understanding so far.
I've got myself a custom built RDWC with changes in hardware to suit space and changes in procedure from standard RDWCs to mitigate things such as temperature issues resulting in algae/oomy growth and all the other issues resulting in temeprature.
Mine is intermittent RDWC meaning the water pump in on a timer to circulate water for 15mins on then 15mins off for 24 hours a day.
I had to stick with this procedure to mitigate the problem of the pump acting as a water heater virtually for my reservoir because it is submerged.
This has worked great, the pump doesn't get hot enough in 15 minutes to cause bacterial growth, I typically run about 7-10 days or once I've added the total system volume in Top Ups I do a system drain fresh water change out.
Until last night when I left the override switch for the pump turned on and I have come out about 24 hours later to do a top up to find the water temperature at 27°C (5°c above the safe 22° to prevent slime) and the ph had climbed to 6.6, growth slowed to 25% and the ppms had risen about 40ppm. When i opened the reservoir lid their was almost like a coloured film on top, in patches, like petrol and oil on water, I would define it as scale, and a medium smell of roots mixed with a sort of smell one can only define as root material decaying. Now this has only gone as far as it can in 24 hours, the roots themselves don't have a slime buildup or any sort of root rot or slimy appearance as of yet, just when I pop the container lid and check the roots for a smell test I got the same smelling damp warm air, it doesn't smell good, but its not at the stage of causing root rot or slime build up drastically if I correct the problem now, and dont let it continue i know i will be able to correct it.
Now ill tell you guys what nutrients im using.
2 plants in a 3 pot (2 plant buckets and 1 reservoir) 60 Litre recirculating system
1x white widow Max auto week 1-2 flower
1x AK47 auto week 2-3 flower
Both on same feeding schedule 800-850ppm
Ph 5.8 temps 22-23°c (72-75°F)
Now I'm sort of well prepared for correcting issues like this if they did arise, and they have due to a fault of mine. Normally I would be fine is just draining the system completly, giving the roots a quick rinse with chlorinated tap water and drain the system again and refill with new pH nutrient rich water, but I literally only just filled up my system 2 days ago, and the ppm is still up around 900.. I dont want to waste all of my nutrients if I dont have too.
I have added bottles of frozen water to bring down the temps quickly and drastically holding them down at around 19-20°c to help kill off bacterial growth and fungi, I also added 6mls of beneficial bacteria (HydroEdge) to the reservoir to see if that could offer me some quick safe results too, although im thinking beneficial bacteria will take a few days if not weeks to take effect, and it might cause more problems using it in conjunction with a mineral descaler like UCRoots
photos provided of HydroEdge and instructions.
I also lowered the ph down to 5.7 as acid helps kill bacteria.
Now I need advice on what you guys would do.
BTW. Im using current culture UC ROOTS which says not to use other sterilisers or beneficial bacteria but I thought I should do something to save it since I will probably end up draining it soon
Since the temperature has dropped to 19° and the ph is 5.7 the smell has obviously lessened drastically in the last 30 minutes, my question is will the plants root zone with the addition of beneficial bacteria clean up the water that had scale build up and will it correct this issue or will it progress further.
I.e if the temperatures rise again for a couple of hours will the water spawn bacteria again and cause slime alot quicker than it would normally take? Obviously the bacteria in the water has to cause some sort of fallout I imagine.
Im just a bit confused as to what to do exactly if I leave the nutrient solution for another 2-3 days will that be okay at maintained temperatures or could it progress further into Root rot and slime on the roots that I can get rid off easily.
Take note guys there isn't any slime or mucus on my roots as of yet, it is mainly on the waters surface and on the pump. Its the beginning of slime so you can imagine the odour it's producing, although is doesn't need a peroxide soak or a H2o2 bath or anything that drastic. Although I'm wondering if I could add a very small amount of H2o2 every few hours for the next 48 hours or something like that to kill the pathogens in the water giving me freedom to continue to top up the system as normal for the next week + to give me the full use out of the nutrients.
Or for safety sake, should I drain the whole system, rinse roots with tap water and flush lines out with tap water, then refill system with RO water, pH balance, add CCH2O nutes and UC Roots and start again and just take the loss on the chin.
It is my first grow Hydroponically and I haven't had anything happen like this along the way, my two ladies are looking very healthy and strong for Automatics so I don't want to do something to stunt them or overly stress them to the point of minimising the yield.
I need as much urgent advice from as many different people I can get, because in about 6 hours - At Most! - I will either fully drain and refill or make amendments based on my own understanding so far.
Thanks guys.
Even tho I am using UC roots which may keep the roots free of mineral scales and leave them suspended in the water, without removing the water with the film or filtering the water again I imagine the problem will remain dissolved in the water and will re emerge in the near future.
Aqua Man

Aqua Man

The oil is biofilm... probably from organics or dying bacteria. Of you have biofm you have poor gas exchange and poor aeration/agitation

Temps don't CAUSE bacteria they increase thier metabolic rates and reproduction. 80f may lead to an issue with o2.

How are you aerating your system?

How often are you using the UC roots? Sounds like you need to use it more frequently or switch to a live system. Personally I prefer live.
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