Maxsea 16-16-16 vs MSU 13-3-15 for carnivorous plants?

[victorhooi]

NB: My original thread with all my links/research got deleted - I've tried to retype it from memory. Sorry if I'm missed any links.

I'm currently doing some experiments with hydroponics/aeroponics for carnivorous plants.

One area I'm really struggling with though is fertilisation. I'm not an expert in fertiliser chemistry, or soil science. I'd love to get some help, or experiences from others.

I've put all my notes below in case it can help other people, or anybody else is able to fill in the missing parts.

1. Maxsea 16-16-16

The traditional consenseus seems to be is to fertilise carnivorous plants with diluted Maxsea 16-16-16, as popularised in The Savage Garden by Peter D'Amato.

I also found this thread on The Sarracenia Forum, where they talk about using Maxsea, and what ratios work. On the last page of that thread, somebody mentions using 150ppm for foliar fertilisation, or pouring 750-800ppm directly into the pitchers.

For some odd reason, the Maxsea website doesn't have any information on the composition, or the guranteed analysis of their products (i.e. the information that would normally just be on the label). Fortunately, Monster Gardens has some of the information typed on their product listing page for Maxsea 16-16-16, and this Carousell listing for Maxsea also has some high resolution photos of the product label:

One of the issues with using Maxsea 16-1616 for hydroponics/aeroponics is that it's an organic (or partly organic) fertiliser. Organic fertilisers tend to be less soluble than inorganic (mineral salt) fertilisers - which means they can clog up filters/pumps or damage nozzles in the system. Furthermore, organic fertilisers also encourage the growth of biofilms in the hydroponic/aeroponics systems, which can be an issue.

Another thing I'm not sure about is what the N source is in Maxsea. The label mentions 10% "water soluble organic nitrogen". I'm thinking this might be referring to urea, but not sure. If it's urea, then it needs to be converted to be available to the plant (e.g. by nitrogen-fixing bacteria, or in solution via hydrolysis - this article had some useful info on urea, and this paper compared urea vs other N sources for hydroponics). However, it seems that urea may not be converted properly/fully in a hydropnoics/aeroponics system without media.

2. MSU Fertiliser

I recently found out about another fertiliser referred to as the "MSU" fertiliser (after Michigan State University, where it was first created), which is very popular in the orchid community. Here's some good resources I found discussing this fertiliser:

• Original article talking about the fertiliser
• YouTube Video from "The Plant Propagator", talking about the fertilise
• https://staugorchidsociety.org/PDF/IPAFertilizers.pdf
• https://www.slippertalk.com/threads/msu-vs-k-lite-plus-fertilizer.59300/
• https://www.slippertalk.com/threads/to-put-records-straight-on-msu.7762/
• https://www.slippertalk.com/threads/msu-fertilizer.3088/
• Guaranteed analysis, EC charts and mixing instructions

The fertiliser comes in two variations - one for RO or rainwater (i.e. low TDS), and one for tap water. In our case, I assume we'd be looking at the RO version (MSU 13-3-15).

There's a number of commercial companies selling the "MSU" fertiliser:

• rePotme FEED ME!
• Tezula Plants MSU Fertiliser 13-3-15
• K-Lite Orchid / Epiphyte Fertiliser (This is a slightly tweaked formula)
• Akerne Orchids Rain Mix (Available mostly in Europe - I found a Amazon listing, with the product labels)

Behind the scenes, apparently nearly all of these are actually made by a single company "Greencare", who also sell it directly (e.g. on eBay):

3. Existing research

I did try looking for any existing papers or research on hydroponics for carnivorous plants and I couldn't find much.

• There's a single paper on Mineral Nutrition in Hydroponically-grown Pinguicula
• Somebody's undergraduate thesis on Drosera and the effects of nitrogen
• Somebody called "Jasper Knight" did a writeup on some trials he did with Borneo Exotics on hydroponics with Nepenthes - however, the document was written before the study was finished (and I can't find any subsequent updated document), and the document has "Exact EC information withheld" - so I assume Borneo Exotics wanted to keep the actual data to themselves.

I'm surprised there isn't more out there - I figured somebody must have done some research into this area - but perhaps I just haven't found it yet?

4. Questions

Has anybody tried the MSU fertiliser on carnivorous plants, and what were the results like? What concentration did you use?

Does anybody know how to correctly "convert" the 150ppm Maxsea 16-16-16 to an equavilent in MSU fertiliser? I know the ratios are different, and I assume N will be the limiting factor. (And yes, I know TDS/ppm is a limited way of measuring fertilise concentrations)

 

[Lloyd Gordon]

Here's the MSDS for MaxSea 16-16-16.
You can't really convert the MaxSea and MSU formulations you mention as the MaxSea has a lot more PO4. Not sure how that would matter practically, though.

 

[jackie quan]

There us also Sea Grow ( brads greenhouse sells it) which is 16-16-16 like sra max. Do note people throw in a couple osmocote pellets when repotting. ( Eg vft ) , recently nutricote (360 day ) mixed with bug bites fish food for vft traps also seems to work. I also see experimental hibbyist had sime success with vft roots growing in a hydroponic setup. Lots of experienmenting growers out there and savage gaedens knowledge base is kinda old news.

 

[crossexotics]

For converting, it is done by matching the Nitrogen ratios, the differences are via the other nutrients. 1 gram per liter of MSU would be 130 ppm of N, with 800 mg per L of Maxsea being identical N for practical purposes.

The organic N in maxsea is urea. The research on urea is almost exclusive for crop plants so there is a strong bias, however many tropicals can use urea without prior breakdown in the substrate but it is mostly known in tropical ag/private hort sector. It becomes a question of which genera however...

MSU 13-3-15 was not used by MSU - only the original Tap water formula was but both ended up with the branding. If you match the N ratios as above and compare the other nutrients, you will see there is essentially zero equivalence between the two formulas. The idea was the original had lower Ca since the calcium was in the tap water used by MSU. So... for RO just replace with Calcium nitrate which required the entire formula to change, not to mention nitrate is not exactly the same as hard water carbonates. I think many growers think RO formula means it is for "sensitive low salt species," it is not!

Which carnivorous plants are you inquiring about fertilizing specifically? The original MSU tap water is not a bad fertilizer but the RO one (most commonly used unfortunately) will cause issues long term even if short term it is positive. The nitrate and calcium is just insanely high for carnivorous plants and most tropicals tbh.

Maxsea still works well via the pitchers for Sarracenia/Helis and as a spray for drosera. Via soil it is less predictable, not because of salts actually, but because of the urea hydrolysis spikes the soil pH and damages the roots severely...