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Machine feeds

Ca++

Well-known member
Any experience with feeds that don't need shaking? Or that do?
I know a few people have used auto dosing kit, and wondered how they went about shaking the bottles, or not. I did once have a feed that said it couldn't be machined. I know the ionic range are not happy, as they use black gunk, that will settle. I chucked in a pump, and it was like a gunk magnet. I'm sure other people have experiences to share. Floranova is gritty, for instance. So too abrasive for many delivery systems.


I have been looking at 2L pop bottles. Making a stand, to have them inverted. Then swapping the cap (which is now pointing down) for one from a smaller bottle designed to drink from. The one's with a nipple that can usually be resealed. This nipple could offer a hose attachment point, for an external pump to send the feed back to the top of the bottle. Get is swirling a little, and the bottles shape should see everything make it's way back to the pump. It's my best idea yet, but I feel there must be others that work for people.


I;m also wondering about tank change intervals. I know some feeds may not actually need one. Others may get a bit toxic, topping up elements that might not of been used. I know the standard advice is two weeks, but there is work towards just replacing what is needed being done. I just don't see the full figures.
 

Orange's Greenhouse

Active member
The usual salt fertilizers (Jacks, Hakaphos etc.) dont need agitation. You dissolve fully (stock solutions of 10 % or more are possible). Sometimes they have a bit of residue but that can be filtered or ignored and cleaned out when the reservoir is scrubbed.

With organic fertilizers you won't get solutions. They are all particles that get broken down by microbes. If they were dissolved it would be salt.

Recirculating systems are difficult. Some elements such as nitrate and phosphate are fully absorbed very quickly while calcium is absorbed much slower and accumulates. If you replenish with the same solution every time it can become toxic. Adjusting pH also adds significant amounts of a specific nutrient.
It's simpler to change out the reservoir every now and then. Measuring the elements and only replenishing what is required is too expensive unless you run 10.000+ plants.
I attached a review article that gives a good description of the topic. If you want to tinker that would be fun and engage you a few years.
 

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Ca++

Well-known member
@Orange's Greenhouse
I'm topping up my F&D each day, after 20% has been used. It's strange to think a tank change will mean 5x more N P K will likely be available that day. It's never been a problem before. Learning can be dangerous :)
I'm in a high calcium area, so that might be the guiding reason I should do a change.

Thanks for the reply, it was useful.
www.actahort.org is new to me. I'm looking for the PDF there now, to get an alternate file type.

@Douglas.Curtis
The airline is quite easy isn't it. That could be useful. I guess a bottle tipped to get one corner lower, could be enough with many feeds. I'm really fond of ionic though, with it's simple 'one bottle' for grow, and one for bloom, approach. It's fully chelated though, with humic products. These cause suspension issues.
If Orange Greenhouse is totally on the money, then an airstone would be ample. I have little pumps that fit through the neck of 5L bottle tops. Actually shaped for the job. So it seems a purely salt feed, would easily stay as a solution. I know the shop has to turn the bottles they stock periodically. Which says the manufacturers are not convinced about them standing around. It's some years since I had a bottle stood long enough to get gritty though. Making slushy noises as you swilled it.

I don't quite feel settled yet. It would be nice to hear of a manufacturer, saying their liquid feeds are okay to stand about.
I can't get a reasonable powder unfortunately.
 

Douglas.Curtis

Autistic Diplomat in Training
I used GH Flora line and Maxibloom dry powder for over 15 years. I assure you, they'll stay in suspension for months in a res without issues. I don't dump my rez till the end of flower and ran mostly DWC. Bottles of Flora will sit around for a few years without issues, and Maxibloom lasts nearly forever when kept dry. ;)
 

Ca++

Well-known member
I have something to think over then.
Using 1part, I can dose the tank as easy as chucking a pump, attached to a dripper over the tank. The flow just needs to be slow, as the electronics will decide when enough is enough.
If I use 2part, the A&B need to be dosed more accurately. For me, that would mean two peristaltic pump heads. About £30 a piece. They can share a driver though, which I can do for about £15. I have spare set anyway, as I use one for the acid. I could perhaps water down the acid. They dose that with the pump and dripper. Giving me two peristaltic sets spare.

I'm going to get on them fake dosatrons when I can. Which is another reason I'm on this topic. In an A&B situation, I can likely stick my nitric in the A (having checked the vendors idea of what A should be). Saving a pump, and making full drip supply automation, a $200 job. I have actually mixed nitric with my 1part, stood it 6 months, then used it just fine. It's not beyond reason, but needs another look. A fake dosatron is $50 and the rest I have. It's good having spares around me, and I don't build panels anymore. I do all I can as modules, having learnt everything should be repurposed one day. Though lets be honest, it is great to make a panel that does everything, just because it's impressive.
 

Ca++

Well-known member
I tried the GH Floranova stuff. It's white clay based, and full of grit. I struggled for a while before noticing the charts give an N expectation, over double what the bottle says it contains. A couple of emails back and forth, and that's me done with them. What they call a guaranteed analysis on the bottle, is a guaranteed minimum analysis when you talk to them. Which they quite rudely said was wrote on the bottle. I dropped the conversation at that. They are struck off.

@Orange's Greenhouse I think I found the document. Bugbee is 2004. It says I need some potassium nitrate, and can about get away with the rest. My zinc will rise, but I like a bit more, as I'm often short and papers on it suggest we should use more. I need to look harder at Mo a know a number of people who just top up, and at least one is a growing super hero.
My N concern with a fresh tank (from reading too much) is quite well addressed there. Telling me the top-up should have double the N of the res. The K almost double. No more P though. Making the Potasium Nitrate look like it could be a rough fit. 13% N and 38% K. A bad balance, but the right things. The K should be helpful, antagonising my climbing Ca levels. I'm really selling this to myself. I think I could need it more than I know.
 

Orange's Greenhouse

Active member
What they call a guaranteed analysis on the bottle, is a guaranteed minimum analysis
That's correct. They guarantee that atleast this much is in the bottle. All fertilizers are labeled this way. The idea being that the customer needs assurance that certain components, especially trace elements, are present and the company won't put more in than they write on the label.
But this also led to snake oil with "improved delivery technology" where a "low" P fert with just 6 on the label is as efficient as a 18 label. Because they write 6 and put 18 in...
You can't use the label if you want to fine tune your fert program. You have to either make everything from scratch (labour intensive) or send it in for analysis (repeatedly, expensive).

I don't think you can mix acid and A fert in the same bottle. Because drifting pH is Independent of top up. Even without a pH probe you can learn how your plants/res reacts and dose x ml per day of acid (accounting for plant size etc.) and prevent major drifts. Then readjusting manually.

Where do you live? You can get good salts that are more horticulture oriented and less cannabis/home gardener specific. I can recommend some in europe.
 

Ca++

Well-known member
I'm in the UK, but not really interested in powdered feeds. I have used the same liquid for decades, and selected my plants using it. It's just too easy, except selecting the kit to automate it. I would look at other bottles, but for powder it's megacrop UK, and they consistently have no stock. They will get me a whole pallet shipped though.

My feed comes as a hard water variant, where they use more nitric in the formula. It's what put me onto the idea. As I say, it's one bottle, and I have put the acid in a few times, and done a long term settling test.
I have not looked up how calnit is made, but suspect using nitric acid on calcium carbonate.

My last dosing system relied on knowing the daily acid use, like you say, you learn to guess. In that system, My drip system ran on a timer, so used the same amount of water each time. The tank filled to a float. So took the same each time. So peristaltic pumps were set on timers, to deliver the same amount. If ran well, but every few weeks I would be changing the timers a little. Many fish tank dosing kits are no different. Just the pipes in them need changing, for suitably resistant one's.
 
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