Autopot Reservoir foam and PPM dropping?

[Bobcharlieeeee]

New to using COCO and autopots, switched over to the reservoir a week ago. Im using a wave maker at the bottom of the tank pointed upto the surface    

 

Im getting alot of surface scum in the res and also its starting to foam up? The surface scum is also in the autopot trays, its like a silvery surface coating. 

 

Im using GA hard water nutrients, i filled the res up originally with 1.2-1.3 EC using Grow A + B, Extra traces, epsom 0.15g/l and also Root tonic

 

 

the foam smells like the Root tonic does, is this causing this issue?

 

The second issue i have that is confusing me is that the PPM's are dropping in the tank, iv filled with an EC of 1.3, this has dropped to a 1.1 EC. i added some more nutes last night to bring it back upto 1.3 rightly or wrongly. Checked this morning and it was still at 1.3ec. i PH'd the res down to 5.5 and checked the EC again, and it has dropped to 1.1ec after PHing the water.

 

Also the PH seems to rise very fast, it rises from 5.5 to 7 in less than a day, is that normal? 

 

  

[Jams67]

Hey bud, not sure how much help I can be as I only started growing this year. I've just about done my 2nd grow both have been in autopots and I've never had that foam on top. How powerful is your wave maker? I use a small submersible water pump (Ehiem CompactOn 300 and 600) they create a nice ripple on top when there is a decent amount of water in the tank and when it gets low it just spits up about 100mm and creates a ripple, the only thing I can think off is the wave maker you have is too strong and causing the reservoir to bubble too much. I've no idea about nutes etc either, but maybe the excessive oxygen in the water is reacting with your nutes and causing ec to drop. Like I said that's just me guessing I'm sure there will be more experienced guys that can give you good advice along soon.

 

My 2 grows I used Canna Coco A&B, Rhizo, Calmag, Cannazym, Cann Boost and PK13/14 at different stages, but for the second grow I started to only use the coco A&B in the reservoir, and anything else was added directly to the tray. Keeps the reservoir much cleaner and doesn't stink so much. I think the main culprits were rhizo and boost but now I only use the res for base nutes.

 

I had originally gone for a water stone before the pumps but read they can raise ph levels so went for the pump instead. I now use the water stone if I use too much PH- and need to raise ph back up. With the pumps the PH will rise but not by that much I started to go down to 5.8/5.9 and by the end of the week, it could be sitting at 6 or 6.1. 

 

[Bobcharlieeeee]

@jams67 @Jams67 its only a 2000l wave maker, the smallest i could get! 

 

I think the foam has come from the Root tonic as it does smell like that. 

 

Im mainly concerned about why the ec is dropping 

 

I think my ph is rising way too fast too, 

 

Think im going to empty and clean the res and start from fresh 

Edited October 25, 2022 by Bobcharlieeeee

[Jams67]

2 minutes ago, Bobcharlieeeee said:

@jams67 @Jams67 its only a 2000l wave maker, the smallest i could get! 

 

I think the foam has come from the Root tonic as it does smell like that. 

 

Im mainly concerned about why the ec is dropping 

 

I think my ph is rising way too fast too, 

 

Think im going to empty and clean the res and start from fresh 

That sounds like a sensible plan mate, that tank probably needs a good scrub and if the foam has been going into the trays I would give all the hoses and valves a good clean too. I would maybe try and just use your base nutes in the res and add the root stuff directly to the tray, and see if that solves the problem.

 

is the wave maker at the top of the tank or the bottom? 

[Bobcharlieeeee]

@Jams67 its right at the bottom of the tank pointed straight up, stuck to the bottom 

[Jams67]

16 minutes ago, Bobcharlieeeee said:

@Jams67 its right at the bottom of the tank pointed straight up, stuck to the bottom 

Ah cool, id heard of some folk having them floating. I thought maybe if that was the case the surface of the water was getting churned up causing the water to foam. Im not sure what else bud, hopefully, you will have a better result after cleaning the res out.

[CDF20]

I am using autopots with canna A and B only with no any pumps at all. Never had any issues. Try without pump mate just to check! 

[catweazle1]

Could there be a wetting agent in one of your additives causing the foaming? Generally it can problematic to use organic materials in a res because of the agitation keeping things moving. Are you recirculating the nutes or drain to waste? I'm not familiar with autopots.

Edited October 25, 2022 by catweazle1

[Wag]

The reason the ec and ph are moving is probably the wave maker. It will do the same with an air pump. Also if you don’t stand your water 24hrs first they will move about. Try running it with no movement with pre stood water, it should be much more stable. Just give it a stir when you check the plants. I think the scum will be from it too. I ran autopots for years with lots of experiments with water pumps and air to very little gain in yield or plant health. Just more headaches. I have also tried organic in them, I ended up with blocked lines.

[Bobcharlieeeee]

@Jams67 Iv emptied / cleaned and refilled the res with COCO A+B and Extra traces last night. PH is now more stable and not rising as fast and the EC has remained the same. Phs to 5.5 last night and it was at 5.8 this morning. No foaming now. Think im back on track.  

 

@CDF20 @WagIv removed the circulation pump now which has helped, i also realised i turned the timer off by accident so the pump was on constant for 24hrs which wouldnt of helped. before i had it on for 15mins every hour.   

 

@catweazle1 the autopots are a gravity system, there is no recirculation or drain to waste. the trays get filled and the plants take up the water. I think it was Growers ark Root tonic that was the issue with the foaming, not sure if its organic but i guess it contains fungi and bacteria? 

On another note catweazle, you helped me the other day with my unbuffered coco issue which sorted the Magnesium issue i was having. a few leaves are now showing slight calcium issue which im putting down to the same issue as i was having before with my unbuffered coco. 

i checked run off of two of the plants last night, put in 1.3ec from the top and was getting 0.9ec for the run off. I ran nutes through until it got back upto 1.3ec. I used Grow A+B, Extra traces and also Epsom salt. Is this the correct way of sorting the buffering issue again or should i use straight calmag for this purpose? 

Unless it was the foamy res with with fluctuating ppm and ph that has caused the issue and the pot ppm to drop to 0.9ec? Or do you think this is still the buffering issue rearing its head again? Or have i been to light on nutes at 1.2ec? Apologies for the ramble 

 

Edited October 26, 2022 by Bobcharlieeeee