[Savetheplants]

Ok so here are roughly the parameters...

Volume 20 gallons
Stock 2 two inch fish
Plants about 15 assorted plants
KH about 170 ppm
GH not measured
pH 7.6
pH w/CO2 7.2
Temp 79 F
Nitrate low (5 mg/l) not usually dosed
Phosphate not dosed
iron dosed
Potassium dosed
light a little over 2 watts/gallon 10 hrs/day
CO2 injected lightly
Ferts Liquid Ferts Macro (-P) and Trace
Water 15% water change twice a week
Algae some black algae on old Anubias leaves
otherwise minimal

There are no snails in this tank. One of the fish is a Zebra Loach but there were no snails to begin with.

The question is why do the tippy tips of the new leaves on two different Anubias plants have a few little tiny holes? Also there is a yellowish splotch on one of the new leaves. I am dosing Seachem ferts minus Phosphate as directed. Could it be that I just don't have enough fish and maybe need to start dosing Nitrate and Phosphate?

I'm so afraid of the algae monster that I haven't been dosing N and P.

 

[Seattle_Aquarist]

Hi Savetheplants,

Welcome to TPT!

Are the tips of the leaves also 'hooking' downwards?

 

[Savetheplants]

Yes they are a little bit. They are new growth about six days old.

 

[Seattle_Aquarist]

Hi Savetheplants,

It sounds like it may be a calcium deficiency, do you have "soft" water where you live?

 

[Savetheplants]

The tap water KH measures 130 ppm CaCO3 but I have not measured the GH. I understand that KH has to do with the buffering capacity of the water but isn't the Calcium in CaCO3 available for uptake? The water isn't soft because I have calcium deposits on the back outside of the tank. I use vinegar to get it off.

The yellow splotch is less than two millimeters wide with two other tinier splotches. Part of the edge toward the tip on the same leaf is uneven and the tip is a little hooked under but not by very much.

Anubias are supposed to be hardy easy to grow plants so I'm disappointed after putting so much effort into this. When two separate plants exhibit the same symptoms you know something is deficient.

Could the lack of Phosphate inhibit the uptake of Calcium by the plants?

 

[Seattle_Aquarist]

Hi Savetheplants,

It sounds like you may know a little about this subject? Yes, high Calcium Carbonate levels can reduce the uptake of Potassium. In your case however this may apply:

Calcium is found in many minerals in soil, but is relatively insoluble in this state. Calcium is not considered a leachable nutrient. Many soils will contain high levels of insoluble calcium such as calcium carbonate, but crops grown in these soils will often show a calcium deficiency.

If it were me, I would first doe a 40% water change if you haven't done one recently. Then I would pick up a small bottle of Seachem Equilibrium and dose it at 1 teaspoon per 10 gallons. That should raise your dGH about 2.0 degrees and make some Ca and Mg available to the plants. The old leaves will not necessarily improve, however new leaves should not exhibit the problem if the issue is resolved.

 

[Diana]

KH is measured in a way that relates it to the way CaCO3 is measured.
When you see KH as CaCO3 this does not mean there is any calcium in this measurement.

Get a separate GH test to find out what the Ca and Mg levels are. This is a combined reading, still does not tell you what the Calcium level is.
However, most tap water with a GH reading over about 3 German degrees of hardness will have both Ca and Mg, but not all.
Does the water company annual report list Ca and Mg separately?

 

[Savetheplants]

The water was 270 mg/l CaCO3 last week. I'm in the process of bringing it down. This tank has been neglected for years and I'm taking it back. Sounds like when the old neglected anubias plants in their hard water got hit with brighter light, CO2 and nutrients they decided to grow a new leaf. Unfortunately, they then found it hard to absorb Potassium on account of the hard water. I did not know hard water could block Potassium.

This is funny because I went into an aquarium store last week to buy some plants and asked them why soft water is recommended for tropical aquariums and they couldn't answer. This was about the time I discovered my tank water was so hard. I instinctively started correcting it but didn't know why it had to be done. Thanks for the diagnosis. I do have a bottle of Equilibrium around here somewhere.

Diana,

Thank you for joining in. I just tested the GH in the tank and in the tap water but could not determine a result! My reagent might be expired. There's no date on the box. So then, I googled my local water quality report. Water total hardness is 119 mg/l CaCO3. Calcium is 29 mg/l and Magnesium is 11 mg/l.