Ok, I give up! What's wrong here?

Posted this elsewhere too:

Ever since I went away for a month in January without being able to fertilize the tank, I've had strange things happening to plants.

When I got back all of the crypts had melted and a lot of the plants looked in bad shape.

But after months of diligently dosing to make sure no nutrients are missing I'm stumped. I'm actually wondering if my substrate has gotten poisonous! (I'm not even sure that's possible ??: ).

Here are some of the symptoms:

- The stem on certain stem plants suddenly starts to rot. On some of them the rot happens somewhere along the length of the stem in one spot only and after some days the stem above that spot detaches from the plant. On some other stems the whole stem becomes soft and "mushy".
- Leaves are coming off of Hygro. Some have pinholes but the really strange thing is that it looks like the "stem" of the leaf has rotted and therefore the leaf has detached.
- Holes in Anubias. this is really strange. New leaves will come nice and green and then suddenly overnight areas of a leaf become "glassy" and then this becomes holes. See picture.
- I recently (two weeks ago) added some Hydrocotyle. Now the leaves are just melting away. See picture.
- I still get crypt leaves coming out of the substrate from the roots of the melted crypts. These leaves grow about 3 to 5cm (1-2") and then melt, starting with the leaf stems.

Now for the substrate. This was originally a Dennerle setup so the substrate is a layer of Dennerle Deponit mixed with small plain gravel. Then a layer of gravel on top of this mix. Dennerle cable heating under it all. Total depth of the substrate is around 8-9cm (over 3").

The substrate was setup up in November of 2003 during a tear down and move of a 200l tank that I've had for 15 years or so.

I have a bit of BGA but it doesn't seem to spread too rapidly. Some strands of thread algae here and there that come and go. That's it re algae.

Here are specs:

- Recently installed an Arcadia Luminaire with 4x 39w T5 Plant Pro bulbs. Previous to that I had 5x 25w T8 JBL bulbs.
- Pressurized CO2 through an AM 1000 reactor on the output of an Eheim 2026.
- pH between 6.7 and 6.9 at a KH of 9 (39-60mg/l of CO2)

Dosing schedule for about 4 months now:

50% Water change day - 3g KNO3, 6g K2SO4, 0.54mg/l of KH2PO4, 10g MgSO4 (most of my GH of 10 is Ca).
Day 2 - 0.15mg/l of Fe from CSM+B
Day 3 - 3g KNO3, 2g K2SO4, 0.54mg/l of KH2PO4.
Day 4 - 0.1 mg/l of Fe from CSM+B
Day 5 - Same as Day 3
Day 6 - Same as Day 4
Day 7 - No dosing

The above gives me a weekly dosing of (I calculate based on 175l of real volume in the 200l tank) 31mg/l of NO3, 1.6mg/l of PO4, 0.35mg/l of Fe, 5.7mg/l of Mg and 46mg/l of K.

I do get bubbles from the substrate if I poke around but no rotten sulphur smell from the bubbles.

Is it my substrate that doing something really strange? Or is there a major deficiency that I'm missing?

Here are some pics:

 

Re: Ok, I give up! What's wrong here?

Just measured the tank water:

Fe = 0.3mg/l
PO4 = 2mg/l
NO3 = 30mg/l

Should I ignore these and still raise my Fe (CSM+B) and NO3 dosing?

 

Re: Ok, I give up! What's wrong here?

Tom, when you've got a moment, would be keen to get your inputs into this issue..

Thanks.

 

Re: Ok, I give up! What's wrong here?

Tom responded on another forum as follows (Tom, hope you don't mind me copying it here):

-------------------
"Laith,

Vacuum the substrate in 1/2 area once a week for two weeks.
Pull plants out, clean well, replant. Clean filters, scrub glas, equipment as needed.

Check the CO2.
The only time I have seen this is if something is very wrong or if I just tossed the plants in the tank floating and ther weeds underneath rotted.

Substrates can go sour, I've been helping a number of folks with heavy Discus loading recently and they had loads of wood, Fish and had not cleaned not uprooted their weeds in a long time. I pull up lots of "mud" in these tanks and this needs removed.

Tanks with swords/pruning only the tops are the most likely candidates.

You are left with only two real options since the dosing is supplying enough of the nutrients/we assume their is ample light: CO2 and the substrate.
I'll assume the filter is cleaned often etc.


This will reset and restore your tank back to a well settled relatively "new" but established tank. It's basic work and over time, people do not seem to tend their substrate or move it around much, too much mulm build up is bad.

In new tanks, mulm addition is good.

In tanks over a year or two, high loading from critters, lots of driftwood, you ought to vac the gravel in 1/4-1/3 or 1/2 sections till you have completed the entire substrate once a year for routine maintenance.

I've always done this as a matter of habit, but have noticed folk's tanks that do not get tended have many issues and algae even if their dosing is perfect.

Once the gravel is vacuumed, the tank balances out well again.
I've redone 6 Discus tanks(just redid a 180 for a SFBAAPS member) and have seen the results.

Regards,
Tom Barr"

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So it sounds like every so often a *thorough* vacuuming is beneficial. By thorough I assume we're talking about deep vacuuming?

Maybe I'll just replace my substrate with Flourite... it should give quicker results in terms of improvement on the current symptoms?

 

Re: Ok, I give up! What's wrong here?

If I decide not to change out the substrate at this time but instead do a thorough deep vacuuming as Tom has suggested, I presume I'll be left with plain gravel and leftover mulm.

Should I add anything to the gravel substrate or just let it be and keep my water column ferts up to good levels?