# [Wet Thumb Forum]-Stunted hygrophila difformis



## TWood (Dec 9, 2004)

I had this plant doing well at one point but haven't been able to get it back. The new growth is very small and stunted. I was using our tapwater (420ppm TDS, GH=24) mixed with RO water to get to about 200ppm TDS and GH=8, but when that didn't work I tried all RO reconstituted with Barr's equivalent to Seachem's Equilibrium. Right now it's at 300ppm and GH=8, NO3=10-20ppm, 3WPG, PO4=2-5ppm, dosing Flourish at double rate, and CO2 is high. Suggestions as to what to try next appreciated.


----------



## Roger Miller (Jun 19, 2004)

Are any other plants having problems? Similar or not.

What is Barr's equivalent to Seachem's Equilibrium?


Roger Miller


----------



## TWood (Dec 9, 2004)

Anacharis, of all things, withers and dies away. Cabomba furcata and hydrocotyle verticillata do fine. 

According to the bag it's:

K2SO4
Ca2SO4
MgSO4+7H2O
MnSO4
FeSO4

According to Seachem, dosing this will provide:

Soluble Potassium (K20)23.0%
Calcium (Ca)8.06%
Magnesium (Mg)2.41%
Soluble Iron (Fe)0.11%
Soluble Manganese (Mn)0.06%


----------



## Roger Miller (Jun 19, 2004)

Did you have the same problem when using your tap water that you have with the reconstituted RO?

Do you have any trouble getting the Barr equivalent completely dissolved?

What do you do to add KH? The ingredients you list for the Barr mix doesn't include anything that will add KH.

Ca2SO4 doesn't exist. It would be CaSO4 or CaSO4.nH20 where n is 2 or less. Or is it something else?

I'm concentrating on the mix because the stunting effect you observe can be caused by a calcium deficiency. "Anarcharis" has a reputation as a hard water plant and that kind of reinforces my concern.

A calcium deficiency in the plant doesn't necessarily mean that calcium is missing in the water. Calcium uptake can be blocked by disproportionate concentrations of magnesium (especially) and possibly potassium. The guideline in hydroponic literature is that the magnesium concentration should not exceed the calcium concentration. I don't recall for sure, but I think the potassium concentration is supposed to be about the same as the magnesium concentration.

I have no clue what the proportions are in the Barr mix. I do know that many calcium compounds -- including calcium sulfate -- are not readily soluble and that calcium carbonate can reprecipitate out of some mixes. If you aren't getting the mix to dissolve completely then the missing part is likely to be calcium. If the calcium isn't dissolving then it could create a very unfavorable Ca:Mg ratio. That's a lot of ifs.

The high potassium content in Equilibrium is a matter of contention. Some people have observed stunted growth when using high potassium doses, and certainly the potassium concentration in Equilibrium can lead to high potassium concentrations. Tom has never really agreed with that point, so if he claims that his mix is equivalent to Equilibrium then it too probably carries the high potassium content.


Roger Miller


----------



## TWood (Dec 9, 2004)

It might be a misprint, it says Ca2SO4 - calcium sulfate. I don't know chemical nomenclature.

I'm adding baking soda to get the KH up to 6 degrees.

There was a period of time when using the tapwater sorta worked, but not all that well. Our tapwater is from community groundwater wells and it's my understanding that the local waterways are groundwater fed except after a rain. There is -nothing- plantlifewise growing in these streams, so there's something way off about the water here. It's 420ppm TDS according to an electronic TDS meter, and 24 GH according to a titration test kit.

The powder does take a while to dissolve, the water stays cloudy for a few hours. If I dump it into the water in one clump it makes a pile that takes much longer to dissolve, so I spread it out.

According to Greg Watson, the Barr mix is at the same ratios as Equilibrium. I'm ready to order Equilibrium itself, but now that potassium issue is a concern. I suppose I could order the individual components from Greg Watson and mix it to a lower ratio.

Thanks Roger,

TW

Edit: The anacharis slowly faded from green to clear leaves, and then they all fell off leaving only the stalks. In addition to the stunting, some of the difformis leaves looked like they've been burnt - they maintain their shape but are dark grey like burnt ash. I did dose the usual potassium (10ppm) in addition to the Barr GH builder, so if it is blocking Ca then that might be contributing.

Edit Two: I have some calcium chloride, would dosing that and observing a change validate the Ca issue, or will it too precipitate out before helping anything?


----------



## Roger Miller (Jun 19, 2004)

The anacharis symptoms sound like something else.

Trace element shortages can cause a number of different symptoms, the most common of which involve discoloration and stunting of new growth. Flourish is a good suppliment, but the concentrations in Flourish aren't very high. Also, hard water may make some of the trace elements less available to plants. I use about a double dose of Flourish in my low-light tanks. In a brighter tank I would use a larger dose. In my brighter tanks I use Flourish Trace and Flourish Iron, which provide higher trace metal concentrations. You might try increasing your dose of Flourish to see if that changes anything.

You may be able to test the question or overcome the problem by adding calcium chloride, but that is not the approach I would take. I've never understood why anyone wanted to use something with the formulation of Equilibrium, so I find it odder still that anyone would come up with fake Equilibrium. The product you get by reconstituting RO water with Equilibrium isn't similar to natural water.

Years ago (August, 1999 to be precise) I concocted a formula for reconstituting RO water using readily available chemicals. This recipe gives a water composition that is similar to average river water.

per 100 liters of water:
7/8 teaspoon epson's salt
2 1/2 600-mg calcium carbonate tablets (pharmacy)
5/8 teaspoon baking soda
3/8 teaspoon potassium chloride (Morton's No-Salt).

per 50 gallons of water:
1 5/8 teaspoon of epson's salt
4 1/2 600-mg calcium carbonate tablets
1 1/8 teaspoon of baking soda
3/4 teaspoon of potassium chloride

Both recipes should give you water with about 3 degrees of KH and GH. If you want a stiffer mix then increase everything in proportion.

Nitrate, trace elements and possibly more potassium need to be added separately. The formula reconstitutes the water, it doesn't fertilizer it.

The recipe suffers from the problem that the calcium carbonate is very difficult to dissolve. Kevin Zippel (then a curator of amphibians at the Brooklyn zoo and later at the Detroit zoo) modified this formula to use calcium chloride and potassium bicarbonate, both of which are readily soluble. His recipe is stated in grams of reagents, rather than teaspoons. If I can find a version that is couched in more useful measures then I'll post it.


Roger Miller


----------



## TWood (Dec 9, 2004)

> Originally posted by Roger Miller:
> 
> per 50 gallons of water:
> 1 5/8 teaspoon of epson's salt
> ...


I entered this into the fertilator at APC, not including the baking soda, and got the results shown in the screenshot below. I must not be understanding the GH and ppm relationships. According to the ppm shown in the fertilator that's about one degree GH when summing K, Ca, and Mg, even less if only counting Ca and Mg. What am I not understanding?


----------



## TWood (Dec 9, 2004)

Also, when using this calculator: http://dataguru.org/misc/aquarium/calKH.asp
I get a different measure of baking soda needed to raise the KH by 3 degrees - 2.88 teaspoons rather than 1.125 according to the recipe above.


----------



## Roger Miller (Jun 19, 2004)

There are a few things you're missing.

Only calcium and magnesium are included in GH. No potassium.

Hardness is not measured by adding the ppm of calcium and magnesium. It is measured as the equivalent amount of calcium carbonate. The equivalent amount is the weight of calcium carbonate that would contain enough calcium to equal the electrical charge on the calcium and magnesium in the water. To calculate hardness from calcium and magnesium concentrations, divide the calcium concentration by 20 and the magnesium concentration by 12, then sum those two values together. Multiply the sum by 50 to get the ppm hardness and divide the ppm hardness by 17.9 to get the degrees of hardness.

(20 is the atomic weight of calcium per ionic charge, 12 it the atomic weight of magnesium per ionic charge, 50 is the molecular weight of calcium carbonate per ionic charge and 17.9 is the conversion from ppm hardness to degrees of hardness.)

The 600 mg calcium carbonate tablets are so named because they contain 600 mg of calcium, not because they weigh 600 mg. The tablets each contain 1.5 grams of calcium carbonate. I made the same mistake the first time I put the recipe together. It is embarassingly well- documented on APD.

If you put those numbers into the fertilator and recalculate hardness you will come out a lot closer.

Baking soda is not the only source of KH in this recipe so you should not get 3 dKH from the baking soda alone. Each calcium carbonate tablet added to 50 gallons of water increases KH by about 8 ppm. In the 50 gallon recipe the calcium tablets alone add 2 degrees KH.


Roger Miller


----------



## TWood (Dec 9, 2004)

Thanks Roger, that's exactly what I needed to get this figured out!

TW


----------



## TWood (Dec 9, 2004)

I used calcium chloride and targeted the middle range of the values shown at the bottom of the fertilator. The KNO3 alone provided all the potassium needed, so that was definitely being high-dosed before. It's been not quite a full day for the tank and there's already a lot more bubbles flying around the tank, so the plants liked -something- better. Hygrophila difformis is quick to react to changes, so I should know within a day or two if this is going to work. BTW, is there a reason why calcium chloride is not preferred?

Thanks again,

TW


----------



## Roger Miller (Jun 19, 2004)

I don't know why the Barr formula wouldn't use calcium chloride. It's easy to come by (sidewalk deicer) and dissolves readily.

In my recipe I used calcium carbonate instead of calcium chloride to get the right KH while keeping my target levels of sodium and potassium.

Kevin's forumula used calcium chloride instead of calcium carbonate but substituted potassium bicarb for potassium chloride. At the time potassium bicarb was not the easiest thing to find. His formula gives more chloride and less KH than mine, but everything is within reasonable limits.

Kevin's recipe is

100 gallons of RO water
17.6g epson's salt
11.3g baking soda
15g calcium chloride
13.6g potassium bicarbonate

Maybe the fertilator will help you work that into teaspoons.


Roger Miller


----------



## TWood (Dec 9, 2004)

I used the mix design in the attached fertilator screenshot. The hygrophila difformis reacted by abandoning the stunted end growth tips and sprouting new growing tips all over, so it'll be a while before I know, but it's probably a good sign.

I ordered the only hobbyist calcium test kit I could find easily - made by Hagen. I have an electronic TDS (Total Dissolved Solids) meter which is really a conductivity meter with a built-in 0.5 conversion factor to convert MicroSiemens to PPM. I'd like to test our tapwater and see, with this additional info, if it can be used to reconstitute RO water. 

EDIT: The TDS meter shows 420ppm for our tapwater, and a GH test kit shows 24 degrees. 24 times 17.89 equals 429ppm, so the TDS in the water is almost all Ca or Mg, correct? Given that, can I just subtract the measured Ca concentration in ppm from the TDS ppm to get the Mg concentration in ppm? Within a rough level of precision, of course, given the measuring tools. I'm thinking that if the Ca:Mg ratio is way off, that I can fix it by knowing these measurements.

One thing that can throw it way off is whether or not the conversion factor in the TDS meter is right. I understand that it is typical to use 0.5 for drinking water, but that conversion factors up to 0.75 or higher can also be used.

Thanks,

TW


----------



## Roger Miller (Jun 19, 2004)

When the growing tip of a stem plant stunts and dies it is normal for the plant to branch. That does't mean you have solved anything. It's also really early to tell if things have changed. You may be looking for your answers to come too quickly.

If you're on a public water supply then the best way for you to get information about the quality of your water is to contact the water utility. Ask for a recent, full analysis. Their "consumer confidence report" is probably not going to tell you what you want.

It wouldn't surprise me if the TDS in your water is mostly calcium carbonate, but no doubt there are other consituents in it.

I've never known any water supply where the ratio between TDS and conductivity was near 0.5. Normal ratios are in the range of 0.6 to 0.7. For accurate results you also need to calibrate the meter. Readings from an inexpensive meter can fluctuate a lot.


Roger


----------



## TWood (Dec 9, 2004)

Thanks Roger,

I have a long experience with hygrophila difformis, and this isn't the first time I've suspected that, under certain conditions, that it is susceptible to potassium overdose. TBarr convinced me otherwise, but once I get this tank back to where I want it, I may experiment with that again.

Here it is before I mucked it up.


----------

