Tap water - why not?

[Tom Reddick]

Good evening all,

Went looking for a good recent thread on this to no avail before posting.

The subjects of the Coryopedilum Chronicles are coming along nicely, but the adductum anitum and randsii are going a bit slow. I have never been a proponent of going too heavy with fertilizer- and little or none at this early stage in life.

So tonight I decided it might be time to switch over to tap water.

I have researched our Dallas water supply and it has been deemed "moderately hard" and I think will give these seedlings the little extra boost they need right now on the calcium front.

Looking back, I am not sure why I went with RO water this time- maybe because kovachii were the last Chronicles I did. In the sanderianum Chronicles and with other Paphs in general, I have always used tap water.

It has worked out well up to now, but clearly there are some nutritional needs not being met. Additionally, buying and lugging all this water around is a pain- and finally, I am not going to be one of those people who makes extensive study of fertilizer and makes custom blends etc. Sure that will get good results if done properly, but as adaptable as most species are- I think it is overkill.

Anyhow- curious to know who else is watering out of the tap, or has in the past, and your thoughts on the practice (Note- I mean with respect to most Paphiopedilums. I understand this is not generally a viable option for Phragmipediums).

 

[SlipperFan]

I use pond water on all my orchids. It is very hard, and I've learned (mostly from Rick) that acidifying it a bit makes a lot of difference. Plants grew well, even Phrags, but my slippers bloomed sporadically or not at all. Since acidifying the water, my multifloral Paphs have been blooming beautifully and my Phrags are finally blooming again.

I had changed from rain water to pond water about a year before my greenhouse was built. The slippers bloomed very well for about two years, then they just stopped. Rick suggested adding lemon juice, which I did for a time. But with as much water as I use, about a year ago I started adding citric and malic acid powders to my stock solution. Now my pH is about 5.5 and it is all good again.

Not tap water, but similar, I suppose.

 

[Tom Reddick]

Thank you for the data points- this is helpful. I also like the treatment options you indicate- those are reasonable measures that I could employ.

For reference- Dallas tap water runs 7.1 to 8.2, and when I was in Austin the water was over 9.0. When I lived in Austin, tap water worked great on the seedlings, and in my Apistogramma fish tank I did 2x weekly water changes adding softener as I refilled the tank and everything flourished (they like a low PH too and respond quickly if they do not get it.)

Those are the data points that have me thinking Dallas tap might be okay for me right now.

One more thought and question for you and others- for which I have no answers or notions- is disparate treatment potentially appropriate for seedlings versus blooming size plants?

In other words- if tap gets a good result in getting seedlings to a juvenile stage- is there any long term harm done?

 

[Linus_Cello]

For reference- Dallas tap water runs 7.1 to 8.2, and when I was in Austin the water was over 9.0. When I lived in Austin, tap water worked great on the seedlings, and in my Apistogramma fish tank I did 2x weekly water changes adding softener as I refilled the tank and everything flourished (they like a low PH too and respond quickly if they do not get it.)

Which Apistos? (I have trifasciata, sp. Tefe,probably agasizzi, and GBR; I'm on http://www.apistogramma.com/forum/)

 

[Tom Reddick]

Which Apistos? (I have trifasciata, sp. Tefe,probably agasizzi, and GBR; I'm on http://www.apistogramma.com/forum/)

Awesome! I used to be on there. If I ever move back to Austin I will get another Apisto tank. Here in Dallas we do not have an LFS that carries a good selection of Apistogrammas.

I had 3 different tanks- one cacatuoides tank, and 2 for hongsloi.

Here is the best shot I have of my best hongsloi pair- doing the mating dance. Would love to see your fish (apologies for the thread drift all- I miss my tanks!)

 

[fibre]

I use tap water all my life long for Paphs, seedlings as wall as adults.
pH 7.5, 240 ppm most from Ca 65mg/l, Mg 20mg/l, Sulfate 20mg/l, Chloride 5mg/l, silicic acid 4mg/l. I use Orchiata and a fertilizer for hard water (Hakaphos blau: 15-10-15). It contains some amount of citric acid. It works quite well for me.

 

[Ozpaph]

I use tap for one greenhouse and rainwater for other. Not sure if its any different.
I must say I would choose rainwater for anitum and sanderianum; delicate by reputation, but no evidence.

 

[Linus_Cello]

Awesome! I used to be on there. If I ever move back to Austin I will get another Apisto tank. Here in Dallas we do not have an LFS that carries a good selection of Apistogrammas.

I had 3 different tanks- one cacatuoides tank, and 2 for hongsloi.

Here is the best shot I have of my best hongsloi pair- doing the mating dance. Would love to see your fish (apologies for the thread drift all- I miss my tanks!)

Really, no good LFS in Dallas? The Fish Gallery (www.thefishgallery.com/pages/locations-dallas) sounds like a good store (the one in Austin better?).

I got my Apistos through our fish club (the general fish club, pvas.com, not the one that specializes in cichlids, www.capitalcichlids.org/forums/). Also there's an importer in our club, www.batfishaquatics.com/)

I'll have to take some pics. My dwarf cichlids are in a community tank, and I think all the trifasciatas are male anyway. I have three show tanks, a discus tank, a planted shrimp tank (with gobies/stiphodons), and the community tank. Here are some pics someone else took: http://gwapa.org/wordpress/2017/06/june-2017-meeting-2/#more-3075

I like the rockwork in your hongsloi tank. You made it yourself? What "rock" material did you use?

 

[terryros]

A reminder that we can't make detailed decisions about our water source without equal consideration of the specific fertilizer to be used, the potting media used, and the type of orchid being grown. The best, detailed discussion of these issues are in Bill Argo's series "Understanding pH management and plant nutrition", a five part series that has been made easily available to us by several members of this forum on their web site. Just search by Bill Argo's name and the start of the title and you will get it. The combination of the water and fertilizer is a starting point, but what you really want is the pH (and probably electrical conductivity) in the media, which is most easily obtained with a pour-through method (described in Argo's articles). You need a pH and EC meter to do this.


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[Happypaphy7]

I use tap water ( NYC tap with pH of around 7) whether I mix in fertilizer or not.
Things grow and bloom well for the most part. No complain really.

I'm surprised you had good results with tap water of pH value 9!

I would think, in general, tap water lack lots of nearly all elements ( especially macro like N, P) plants need other than Ca & Mg.

 

[naoki]

Water uptake by roots is passive. So the difference in the solute concentration between inside and outside of the cell membrane influences the uptake rate. So if TDS is high outside of the root, water get removed from roots, and roots/plants get dehydrated. This is why you want to keep the TDS lower than a certain level. If we use tap water, there are lots of solutes which are useless to plants, and they counteract against water uptake. This is why we want to control what solutes are in the water by using RO + fert. instead of tap water. We do know what are the 17 essential elements (absolutely required for almost all plants), but we know less about the beneficial elements (something required or helpful for certain groups of plants). So adding back impurity 'might' work. But I think most people add tap water as a cheap way to increase Ca, Mg, and S if they think these are beneficial (I'm not 100% convinced).

That's the theory, but in reality, plants can obviously tolerate moderate level of TDS. Especially, if plants have enough access to water with decent air humidity, reduced water uptake might not be a big deal (i.e. not the limiting factor). When I moved up to Alaska, I didn't know how hard the water is here (around 800-900ppm TDS) and how low the humidity is (20-40%). I killed all orchids (well, I was a bit busy around that time)... But before that I could grow orchids with tap water + fert. without any problem in NC (less than 200ppm TDS, I think).

I used to grow lots of aristo, too (well, maybe about 10 species) when I was in high school! I can't get any here, so I just have basic planted tanks now. It looks like that you have a nice planted tank, Tom!

 

[Happypaphy7]

Wait, I just checked 2016 water report for my city, and I'm shocked to see the TDS level is 500 (ml/L)! A lot higher than I thought, or one I saw in the past report.

I normally use it straight and sometimes add fertilizer in the tap water.
I don't really have practical concerns, though.

pH is also given in the range of 6.8 - 8. When I tested with a simple pH testing paper, it came out neutral.
With fertilizer added, the value was around 5.0-5.5.

Naoki, do you know general acceptance level of TDS by orchid roots?
I would assume it would be lower than typical plants whose root grow in the soil, which I would think to have more tolerance to higher TDS level.

Also, certain things had very high numerical value, but than their unit was different by A LOT like mg/L vs. micro gram/L, etc.
Manganese was like 300 micro gram/L. I know my fertilizer bottle lists Mn and it is a trace elements. hopefully it's not an overdo.
At least I don't see typical signs of Mn toxicity. lol

 

[Tom Reddick]

I like the rockwork in your hongsloi tank. You made it yourself? What "rock" material did you use?

Company in Texas that makes synthetic rock wall backgrounds- you just buy the size you need and then put it in place with silicone. Looks great and no hassle.

Thanks all for compliments on the fish tank and also for the further discussion on the water issue. I am doing some more research along the lines you have suggested.

For the moment- making the switch. I feel fairly safe doing it due to both past history and the fact that right now I am focused on deflasking Paphs and getting them to juvenile size- a period where I find they can be very fussy about fertilizer.

 

[naoki]

Naoki, do you know general acceptance level of TDS by orchid roots?
I would assume it would be lower than typical plants whose root grow in the soil, which I would think to have more tolerance to higher TDS level.

Do you mean TDS of 500mg/l (instead of ml/l)? That seems to be quite dangerous, but your plants seem to be doing well. I thought that NYC water is pretty good for plants.

No, I don't know the tolerance. It is probably not a simple matter since sensitivity to salt is likely to interact with the environment as I mentioned earlier. There are some papers which experimented with different fertilizer concentrations for orchids. In Disa, which most of us believe that they are sensitive, they could do well at an amazingly high EC. I don't remember the exact values, but I was very surprised.

Aside from the scientific evidence, I vaguely remember that Antec Lab web site used to say about the TDS of water (some number based on anecdotal experiences, I think).

 

[myxodex]

I have always used rain water because my tap water is very hard; 298 mg CaCO3/l. The trouble with this water is noticeable with general house plants in that it produces a limescale crust on the surface over time, so increased repotting frequency is required.

Now I add a bit of tap water to the rain water for my orchids (especially for paphs) in order to prevent progressive acidification of medium and this has solved the problem. So my approach has been to follow the idea of matching fertilizer with water, so in line with what fibre and terryos posted above. I second the terryos comment about the Bill Argos article, it was very helpful for me.

Like the fish, cichlids are IMO the most interesting fresh water fish to keep,... so much character. Have kept various Apistos before and bred Pelvicachromis taeniatus, ... seeing the communication between the parents taking turn to watch over and school a shoal of fry around the tank was so cool. Owing to hard tap water and the hassle of having to filter it before water changes, ... I now keep a Malawi community setup, much easier.

 

[Linus_Cello]

Company in Texas that makes synthetic rock wall backgrounds- you just buy the size you need and then put it in place with silicone. Looks great and no hassle.

Can you post the TX company?

 

[Happypaphy7]

Do you mean TDS of 500mg/l (instead of ml/l)? That seems to be quite dangerous, but your plants seem to be doing well. I thought that NYC water is pretty good for plants.

No, I don't know the tolerance. It is probably not a simple matter since sensitivity to salt is likely to interact with the environment as I mentioned earlier. There are some papers which experimented with different fertilizer concentrations for orchids. In Disa, which most of us believe that they are sensitive, they could do well at an amazingly high EC. I don't remember the exact values, but I was very surprised.

Aside from the scientific evidence, I vaguely remember that Antec Lab web site used to say about the TDS of water (some number based on anecdotal experiences, I think).

Oops!
Stupid me. I was sleepy and was not reading the table correctly!

Yes, the unit is mg not mL.
Also, the value 500 is the maximum allowed value, phew~
The range found among over 300 samples is given as 42-292, and the average value is 84. So, it is very good!

Calcium carbonate is 33 average with the range being 19-119, which seems quite big.
Magnesium is 2.5 average with range of 1.1-11.
Units for both is mg/L.

 

[NYEric]

 

[Tom Reddick]

Can you post the TX company?

https://www.universalrocks.com/aquarium-reptile-pet/backgrounds

They are awesome!

 

[blondie]

To be honest I use tap water for all my orchids I don't follow the instructions on the fert or sea weed extract that in use as I always do it under the recommendations. I get the odd brown tips on certain phrags andsome ceologynes but in all honestly that's only happened this year, so I think it is more due to cultural problems like low humidity.

I have never tested our water ever, I get lime scale at home but not to bad.

But I fill the water but,a week before I use it so it warms up in the green house.

I have recently decided to change the water for the phrags to rain water, but when it comes to winter the rain water will be to cold and won't warm up enough to use for them. So I'll go back to tap water.