Res changes

[Monty Bong]

Seems to be a bit of a conflict of opinion, like there always is when you ask canna growers a question lol

I haven’t done a res change yet, my plants are looking ok and they’ll be 3 weeks from germination this weekend. I think the best thing I can do for now is keep doing what I’m doing, checking the level, the EC and PH, topping up with adjusted water when required. I’m currently feeding at EC 1.2 and PH 5.9. and the plants seem happy for now.
As this is my first go at hydro I don’t plan to veg them for much longer, I just want to whizz through this grow, gain a bit of experience, then on the next run start fucking about with, topping, lst, bloom boosters, etc.
So if they continue to grow the way they are going I think flip them in the next week or so, wait for the first pre-flowers, then do a full res change and replace grow nutes with bloom and see how we go.


Thanks for the input guys, it’s appreciated.

[Samwise Gamgee]

Hi Monty,

I grow in coco and used to recirculate using a dripper system, the main problem you get with this type of feeding is that you dont know how much NPK is in the reservoir after a week, as EC doesn't give you that much detail. Your plants in veg can deplete nitrogen pretty fast, so if you have been using the same feed for a while you can sometimes find, even though the EC hasn't dropped much, you start getting issues.

I have moved to Auto Pots this grow, and bought the XXL version, and growing two plants, a 47 litre reservoir pretty much lasted me 3 weeks. But because this gravity fed rather than recirculating I don't need to worry so much as NPK ratio will be consistent.

Recirculating thou, I would change my reservoir every 7 to 10 days, but then the run off in the reservoir I would use for the plants in my garden, so nothing goes to waste

[Monty Bong]

Hi Monty,

I grow in coco and used to recirculate using a dripper system, the main problem you get with this type of feeding is that you dont know how much NPK is in the reservoir after a week, as EC doesn't give you that much detail. Your plants in veg can deplete nitrogen pretty fast, so if you have been using the same feed for a while you can sometimes find, even though the EC hasn't dropped much, you start getting issues.

I have moved to Auto Pots this grow, and bought the XXL version, and growing two plants, a 47 litre reservoir pretty much lasted me 3 weeks. But because this gravity fed rather than recirculating I don't need to worry so much as NPK ratio will be consistent.

Recirculating thou, I would change my reservoir every 7 to 10 days, but then the run off in the reservoir I would use for the plants in my garden, so nothing goes to waste

That’s interesting Sam, thank you. I think I’ve been quite lucky so far, my plants are coming up to 4 weeks veg now and I haven’t yet done a res change, just topping up and they’re looking pretty healthy. They’re going 12/12 very soon so I think a res change is now immanent. I’m going to see how flowering goes and make a decision on how to go forward. To be honest doing a res change every 7 to 10 days would be difficult, so maybe hydro isn’t ideal for me as a grower. I’ll see how this grow pans out and maybe go back to what I know best… growing in soil.