Top of resovoir stinks


I’m using a 55 gallon black top of res with a sealed cover. The temps in my res are running around 81 degrees. I have a chiller in my hydro system and the water is at 68 degrees. My concern is the top of res smells moldy/mildest. I’m using current culture nutrients bloom a and b, uc roots, and cal mag. I have a water pump in the res with a tube running from bottom to top constantly circulating the water, but no air stones. I’m concerned that there is going to be mold/algae forming in top of res and flowing into my hydro system. Is this a problem. Should I be worried the res temps are 80plus degrees even though the hydro system is set at 68 degrees. Any advice is always appreciated!!


I’m not a hydro guy other than trying out coco , but have tried putting a chiller in the res?


Should be like 65 degrees I think so no you have the wrong temp and I never did hydro


@ktreez420 @Majiktoker @Donaldj @garrigan65


You are using a sealed system? I just want to clarify
Your res temps are far too high I would flush system then run a h2o2 soak for an hour (peroxide) at 10ml per L then refill res you need to keep res temps cooler so if your chiller isn’t working contact the supplier. 68f would be perfect temp and I suspect smell would be result of bacteria or root rot starting


Thanks buddy not my cup of tea :coffee:


@Donaldj I’m sorry I don’t think I explained. The smell is coming out of top of res. The system is 5 days old only, 5 day old water, nutes and the top of res itself. When I say sealed I’m referring to the top of res being sealed. It’s a 55 gal black drum that has a removable cover that seals it. The temps in the res are actually at 80 degrees now. I do have a water chiller but that’s on the actual hydro system only, water from the top of res does not go thru the chiller, only water from the hydro system itself passes thru the chiller. The temps in the hydro system itself is 68deg. I’m concerned that with the temps in the top of res so high and the smell so bad, that when the top of res feeds the epicenter I’m allowing contaminated water to enter system.

Sorry I didn’t explain it properly the 1st time. Writing was never my strong suit​:grinning::grinning::grinning:


If your res feeds entire system than yes it should have an air pump and yes the temps still need to be kept cool. This is a nutrient rich solution meaning any bacteria or algae could easily live in it and the pump inside it is likely generating heat if I understand the description?


Yes @Donaldj there is a water pump in the top of res. And I believe u are correct, that’s probolt generating the extra heat. I’m wondering if I remove the top of res cover and keep it open and run a fan across the top of the res it will cool it enough? I will defiantly drain the top of res, clean and disinfect and start fresh again. At this point purchasing another water chiller just for top of res is not gonna happen. Can’t afford it right now so gotta try and figure out other alternatives to lower temps. Any suggestions??


Ice bottles reducing pumps on cycle using an air pump to circulate res freezies work nice though like ice bottles but easier to rotate and take less space in freezer and res


Reducing pump on times = AWESOME IDEA!! Do u think an air pump with a good size air stone in the res will work as good as a submersible water pump circulating water from bottom to top?


@Donaldj if algae has formed in the hydro system causes by hot temps in top of res I should add some hydrogen peroxide? Is it ok to add hydrogen peroxide to the hydro system with plants in there currently?


yes it would be fine to add peroxide and an air stone will circulate res nicely with far cooler temps produced I would leave other pump on a switch to circ res daily once or twice for few minutes to mix anything that settles but otherwise air stone will keep it mostly mixed


@Donaldj thanks so much for all your time and help!! Greatly appreciate it!


@Donaldj do you have a recommendation on hydrogen peroxide. I see 3% all the way to 35% with several options in between. Looks like most rec the 35%, but don’t clarify what the mixture should be per gallon. I’m using a 8 8gallon hydro system with an epicenter. Beloved totals 72 gallon system when full.



You don’t want to leave the lid off of your res. Exposure to light will have it growing algae too.