Request: Sanity check my fertilizing regimen please!

[Itr_hybrid]

Hi folks,

I would like to ask a favor and have the experts here review my current feeding regimen and let me know if it looks good. In general I get fantastic growth both roots and leaves with "okay" blooming frequency. My phals in particular tend to grow well but bloom rarely. I am also getting a mix of blooms and blind sheaths on my Catts. I also find that the plants grow like weeds under the lights but when I move phals and paphs from the LED lights to windows for a bit it often triggers a spike in plant that grow for years under the LED lights without blooming.

My growing conditions:
- I grow indoors under bright lights
- Platinum LED 300 watt lights 4 ft away (phals)
- Platinum LED 600 watt lights 4 ft away (catts, etc.)

- I run a hudimidifier any times the lights are on. I also run a fan 24X7.
- Temperature is a steady 84 degrees during the day and 70 degrees at night.
- 80% of my collection of 50 or so orchids are in SH (LECA) with the rest in a mixture of Bark or moss.
- Lights are on for 14 hours / day

My current watering / fertilzing regimen is the following:
Water is reverse osmosis. All of the below is per 5 gallon bucket.
- 1 Tablespoon of K-lite for RO
- 2 Teaspoons of Cal-Mag
- 1 TSP of Physan-20 (preventative - mostly for algae in the SH)

I water / fertilize weekly by drenching the orchid in the above mixture in a sink. Fill it to the top of the pot and let it drain down to the SH drain holes. The only other watering I do is a mid-week top off of the SH plants and/or dry non-SH plants with just straight RO water.

So my question is basically does the Nitrogen feeding rate, Cal-Mag, etc. look right? And is there anything that might be hurting the blooming on the phals, catts, etc.? Open to any advice on fertilizing or other cultural angles. Thank you!

- Phillip

[Shadeflower]

Hi phillip, still trying to find most of those answers myself too but what you are describing possibly sounds like a temperature issue. Unless you are being impatient and the plant is not mature enough, that seems to be my main problem. A phal Tetraspis produced a flower spike over a year ago, then stopped. I thought I was doing something wrong but what could I do but keep caring for it. This year it produced a second spike then stopped. I could not get my head around it and I don't want to jinx anything but finally I have flowers being produced on both spikes now, ever so slowly but the patience seems to have paid off.

I am having the same issues as you with my dendrobium atroviolaceum which is being grown under artificial light and should be flowering but isn't. I've heard some are harder to flower under artificial light than others and I am temped to put in into the sun but I will give it one more season before I try to change things.

As to the fertilizer, I usppose you don't have a ppm meter then. You should be able to find one for under 10 dollars on Amazon. Even the cheapest one you can find will give you a better idea than you have now.

You can ask the experts but I'm not sure the information is there to judge on that. Like to me 2 teaspoons of cal-mal per 5 gallons seems like a lot on every watering but it might be the right amount. If you had a ppm meter to measure the increase those 2 teaspoons change the water by then you will have a good idea.

The general region Cal/Mag should be in is 50-100ppm each.

So If your RO water starts off with 15 ppm, you add 2 teaspoons of Cal Mag and it goes up to 165 (increase of 150, which will be roughly 100 Ca and 50 Mg) that would be ok and the upper limit of Calcium and Magnesium you should be feeding but I was feeding only 1ml per 5 gallons when I was feeding cal-mag (mine was in liquid form) so it's hard to compare. 2 teaspoons might be the same, it might be a lot more.

Once you have added the Cal-mag and you add the K-lite you check the overall concentration. If you water with fertilized water every time it should not go above 250ppm in total. If you feed once a month or so then the total can be higher like 500-700ppm but if feeding regularly then much smaller doses are needed and if you already add 150ppm with the Cal-Mag you only leave yourself 90ppm for all other Nutrients to not go over the 250ppm max but I am only guessing the amounts. 2 teaspoons might be more than 150 (which would cause flowering issues) or it might be less.

Even at 150, if the total you can feed is 250ppm then you are only leaving yourself 90ppm for the K-lite.

The ratio's to aim for are

Nitrogen: 20-100ppm (100 being the higher value for less frequent feeding and 20 being the lowest amount for regular feeding on every watering for slow growers)

Potassium: 20-100ppm

Calcium: 20-100ppm

Magnesium: 10-50ppm

Other Trace Elements: 50-100ppm

Ps: If I am not mistaken K-Lite already contains plenty of Cal-mag. If that is the case I think that is your problem or at least part of it. You are essentially feeding the Cal-Mag twice, once with the K-lite and your own dose on top.

PS2: I have mentioned I believe Potassium is needed in the same quantities as Nitrogen, K-Lite only contains 1/10 Potassium as Nitrogen. I know people swear by it but it might be worth considering too. It is very easy to switch to a fertilizer that is not light in K - but I am adding that note as a last ps and just my observation that K-Lite was developed for a certain type of orchid that had a symbiotic relationship with ants receiving all their potassium from the ants and thus K-lite was born (maybe I am wrong about that, that is my understanding but I am just an observer across the pond who can't even buy the stuff, I've heard great things from people using it, it just doesn't make any sense to me to use it for orchids that don't have a symbiotic relationship with ants and my research has shown they need it to flower well..) Maybe switching to a K-complete fertilizer would get better results. Just trying to find the answers you are looking for but I am known to overthink things so ignore me if you like your fertilizer. We need more people testing it to see if it does give better results or not so that is a reason to keep using it. Maybe one day they will bring out a k-lite in Europe and I will be amazed.

[estación seca]

Welcome to the Orchid Board!

Don't mix Cal-Mag and regular fertilizer. Apply them separately. Calcium may precipitate out if you mix.

Consider varying your daylength through the year - less in winter.

[camille1585]

Welcome to Orchidboard!

The problem with your Phals might be the (high) steady temperatures. In order to produce spikes, the typcial winter/spring blooming Phals need to be exposed to a general decrease in both day and night temps for a couple weeks in order to bloom. Commercial growers maintain Phals in a vegetative state with temps over 80F and when they want spikes, they drop it lower. As long as the temp stays above that, they will not produce spikes. In most homes, with plants growing near windows, the natural drop in temps at the end of summer is enough to trigger blooming. I think what's happening is that the conditions in your grow area are too constant, and lacking natural blooming triggers (daylength is one for Catts).

As to your fertilizer, k-lite already contains calcium and magnesium, and is designed for RO water, so I don't think you need to be adding any more, certainly not on a regular basis. As to the amount, it seems about right. it works out to 0.6tsp/gal, which is 113ppm N, which is fine for a weekly feed. (assuming I converted tbsp to tsp correctly, why can't the US just use the metric system?)

[Itr_hybrid]

Thank you for the input everyone. Lots of good ideas here. Anyone else have a perspective on the potassium levels and possibly switching to the non K-lite MSU formula with more potassium?

[Shadeflower]

Originally Posted by Itr_hybrid

Thank you for the input everyone. Lots of good ideas here. Anyone else have a perspective on the potassium levels and possibly switching to the non K-lite MSU formula with more potassium?

There was a thread about it, let me find it..

K-Lite has been around a few years now... updates? - Orchid Board - Most Complete Orchid Forum on the web !

So the quotes were:

From what I observed (as a hobbyist) it has caused me to no longer use it. I have tried to make it work for my growing conditions and my preference of species and I have found it to be less effective than other options. I used it for 18 months so I believe I gave it a fair shot.
...
plant reactions during Klite use:
-root growth in all plants was encouraging and productive
-leaf growth was discouraging and slow
-bud blast was more evident and prior, not an issue
-multifloral species produced rot easily
-I rotted out a gigantifolium during this time. I have never rotted a paph in the 7-8 years I have grown them until this point. An armeniacum album also rotted. I had never killed a parvisepalum paph until this occurrence.
-leaf growth was weak by comparison, leaves would flop or worse, not grow very quickly and when stagnant in growth, they would develop infections near the base where the leaves touched. This was most evident, if not a constant variable that occurred in every paph species outside of the parvi-Brachy group
-parvi section paphs responded without major incident or noticable negative effect, same for Brachys. Although results were not negative, they were not encouraging either.
-Chlorosis, and leaf pigment in MF species was pale and inconsistent. Some leaves have even turned white, absent of any pigment. Leaf mottling in parvis section plants was bland by comparison. Many plants such as micranthums, showed less contrast and less shine.

Since stopping Klite I have leaf mottling that I would consider to be more appropriate. I have leaves in plants that are growing aggressively. I now have plants putting out 2-3 new leads on unbloomed growths. I also have buds or blooms on very small plants (my preference)
for example I have blooms on the following plants with a 8 cm LS and only 3 leaves- niveum, fowlei album and micranthum var. eburneum.

My experience is that I would not recommend using it for species outside of Parvi and Brachy. I would imagine I could have elaborated further, but perhaps this sums up my experience in a way that others may find useful.

I personally don't see good or bad. I switched back and forth only a couple time. My bias is that I generally don't get convinced without a controlled experiment or other strong quantitative data, though. However, I'm thinking low K is good enough (and it could have a hypothetical benefit of reducing TDS as Mike Stone mentioned).

To be honest, we have reduced our use of K-Lite as our primary fertilizer, because 30-10-10 and 10-52-10 (both urea based) are producing better results for us in terms of leaf size and leaf color (green rather than yellow-green) - especially in Phrags. That is not to say K-Lite doesn't work well, it just doesn't seem to work as well in our growing environment as the others.

Following on from comments by Bjorn's and Chicago Stud, I have used the K-lite at various times in between using Akerne, which is an MSU equivalent of 13-3-15 with Calcium and Mg. I use RO water and have done so for a quite a few years so I can monitor what the plants are getting. I have had some excellent results with my mainly paph MF collection while using the Akerne but when I use the K-Lite, the effects of yellowing of the leaves is very apparent in a short space of time. There doesn't seem any improvement in root growth either so I revert back to Akerne

I started to have some of the same issues after a good start with it. I switched back to my old fertilizer, after using what I bought, and repotting this spring. I thought I was the only one having issues until you mentioned it.

My own great experience with K-Lite with my entire collection - paphs, phrags, catts, oncids, encyclias, vandaceous of all sorts, including neos, phals, pleurothallids, etc. - may indicate that my supplementation with KelpMax and Inocucor Garden Solution is "filling in some blanks".

Lance - Didn't notice any disease or pest problems while using K-Lite; just the yellowing leaves and a general slowing of growth in Paph/Phrag compots and seedlings.

Marco - I used K-Lite dissolved in RO water for about a year at 15-20 ppm [N]. Every fourth watering, I flushed the pots with straight Chicago (Lake Michigan) water which had a TDS of 220 ppm, for the micro-nutrients. During that time I noticed a gradual yellowing of non-Parvi Paph. leaves and Phrag. leaves - especially besseae and it's hybrids. Prior to K-Lite , I fertilized with Miracid 30-10-10 (which is urea based) at a 70 ppm [N]. After discussing besseae culture with ST'er "John M" I began alternated the 30-10-10 with 10-52-10 which is also urea based, and achieved the best plant growth I've seen in a couple of years.

I have been using K-lite for just over a year and the plants are still green. Those dose a is 50 ppm N (1/3 tsp in 1 gal). I grow semi-hydroponic. In summer the plants stand in the K-lite and are misted daily. In winter they stand in RO and get misted with K-lite every day.

The only exceptions to the generally good growth are a spicerianum that seems to be going backwards. My roth and St Swithin also seems to be stagnating. It grows new leaves but only at the expense of an old leaf. The roth is also a bit yellow. Perhaps it needs a higher dose? The roth gets a lot of sun so perhaps it is pale because it has ample light?

My problems with the exclusive use of K-Lite started to occur after one year.
It wasn't pretty.

I too had problems with using K-lite and RO water. My plants seriously became bleached. Crushed oyster shells made things worse.

I've been using pure urea and 30-10-10 urea based exclusively (with tap water) for at least a year now. I am happy with the results. I do supplement with Kelp (Kelpmax from Ray and Seaplex), fulvic, humic, and amino acids. I also used to adjust my pH close to 6.5 with phosphoric acid but I haven't in a while. Plants don't seem to mind.

I do try to go light on K whenever I can. I do believe it makes a difference.

I did have problems with orchiata as well but now that i'm using Urea, and watering more often, plants in it are growing like crazy.

I think it's the combination of K-lite (lack of ammonium N)my tap water, and underwatering (and the lime in orchiata) that made it not work for me.

The odd plant, like a phrag besseae and a roth did seem to develop some browning on the leaves but this has since stopped. Apart from that I didn't notice any significant problems, however, the plants looked weaker and with the yellowing leaves it wasn't positive.

I've been using K-lite for about two years consistently at ~10 ppmN at every watering in RO water. Although I didn't see much growth, all my plants were still totally fine. In the past six months, I made a small change thanks to the discussions here by adding back 10% of our municipal water and I have seen a marked improvement since. We get a yearly report on water quality and even though our water supply is really hard, there are definitely a lot other additional micros in there when used at an average of ~50 ppmTDS with ~10 ppmN K-lite. I'm actually thinking of cutting K-lite back a little further to keep the final TDS below 100 ppm. The only additive I add is a drop or two of Superthrive (when I remember) just for a bit of NAA action.

I visited Hausermann's Orchids in Villa Park, IL this March, and saw some of the largest, best looking Parvi's (both species and hybrids, but especially Paph. malipoense) that I'd ever seen. I asked Jim Hausermann a lot of questions re: their culture and he said they were fertilizing with a urea based fertilizer at a [N] of 170 ppm (!) and a TDS close to 500 ppm (!!!) This is certainly contrary to the low-dose direction, regardless of natural habitat conditions. And yet the plants looked beautiful..... When asked whether they had done any testing of low K fertilizers, he said they had done so on their Phalaenopsis and the result was yellowing of the leaves and shorter flower stems, so they discontinued the use of the product.

I started using K-lite last fall when I got my r/o system. Into the first of this year, I had a lot of poorly growing Catts. As a matter of fact, I lost a lot of plants - which surprised me. Seedlings that should have started taking off when the days got longer were struggling. Phrags are struggling. (just got Paphs w the recent auction so can't say). Last week I stopped using K-lite. I didn't see this post till this evening - it's been a long week.

Weak, spindly growth and in some instances followed by rot. Nothing had changed but the fertilizer and r/o water. I was thrilled to not have the salt build-up using the r/o water. But something had gone wrong.

I am now using Miracle gro for orchids (I had invested in K-lite after using up my other fertilizers), which I had on hand.

I usually don't post my growing because I don't like to get into debates about what caused what. I am pretty sure in my growing conditions what I see everyday. I tried lowering my K, then my fertilizer concentration then my urea supplementation after reading all the hoopla. I am so sorry I did. I got decreased light tolerance. I kept having to decrease light on time and distance from the light on the indoor orchids. Decreased growth and to top it off a pretty severe fungal infection. This is only after maybe 6 months. I also supplement with co2 and grow at higher temperatures than most and I used to get amazing growth with rich green leaves. The plants couldn't handle it. I went from having amazing growth to problem after problem. I have gone back to a balanced fertilizer at 300ppm supplementing again with seaweed and urea. The plants seem to be recovering but it was a nightmare. I really am disappointed in myself for getting caught up in a trend that I read about and others told me about when I had a system that was working well for myself and some other amazing growers.
...
I used to be urea crazy. Never had a problem. Then I reduced K. Then I started having problems. Blamed it on the UREA. So I decreased fertilizer concentration totally after reading these forums. Had more problems. Read all this low light stuff so I decreased daylight which helped. Then my leaf growth started stunting. Then color kept getting less rich. Then I got a nasty fungal infection. That was it. I have gone back to my old regimen and in 2 months they are mostly looking great aga

in.

[Ray]

Originally Posted by Itr_hybrid

Thank you for the input everyone. Lots of good ideas here. Anyone else have a perspective on the potassium levels and possibly switching to the non K-lite MSU formula with more potassium?

If you look at the chemical makeup of an orchid, it is about 90% water.

If you look only at the dry material, about 90% of that is nitrogen, about 9% is P+K+Ca+Mg, and 1% is everything else, combined.

The nutrient content of a plant is more of an indication of "what it has been getting", rather than "what it needs", but considering that orchids have evolved to thrive under such conditions strongly suggests the two are at least relatively close.

Phosphorus is rather unique, because a plant will take up every smidgen of phosphorus it can find, whether it needs it or not (and it's apparently not in huge demand, but as been stated, orchids are pretty undemanding of fertilizer at all), and socks it away in cell vacuoles. Unfortunately, it has been shown that if a plant has accumulated too much, it can actually preclude the uptake of calcium, which can be quite detrimental.

The base concepts behind the K-Lite formula were to more closely mimic what the plants see in nature, and to provide enough P & K to meet the plants' needs without accelerating the accumulation issue.

I was the first user of the product. My plants grow and bloom quite well, having received no other formula since December of 2011, although they have been regularly supplemented with KelpMax that does contain a minuscule amount of P & K since it's a plant extract, and a plant probiotic which naturally enhances nutrient uptake.

[Itr_hybrid]

Hi folks,

Great discussion. Just recapping a few of the ideas for me to try.
- Cooler temps to trigger the phals
- Possibly trying a higher potassium version of MSU
- Varying light duration with the seasons

One follow up question - Do I need the additional Cal Mag with the MSU fertilizers or is that just overkill?

[camille1585]

Originally Posted by Itr_hybrid

One follow up question - Do I need the additional Cal Mag with the MSU fertilizers or is that just overkill?

If you use the MSU for pure water formula then Ca and Mg are included and the fertilizer is designed to cover the requirements of these nutrients for most orchids. So I would say no, extra supplementation is not needed.

I know that there are some types of orchids (subgroup of Paphs I believe) that have higher requirements than average, and maybe for those an extra dose of Ca and Mg would be needed, but I am no expert on the matter.

[Dusty Ol' Man]

why can't the US just use the metric system?

Because, Camille......just because.