Hello,

I have a 150 litre tank, with 3x40W tubes, DIY CO2 and PMDD, soft
slightly acidic water. Fish load is moderate and the plant list is :-

two small echinodorus (standard issue ones)
one very large amazon sword
one medium sized echinodorus rubin
quite a lot of twisted vallis
some java moss growing on wood

I used to use Tetra plant food and was constantly pulling out twisted
vallis as they were spreading everywhere and taking over the tank. Since
I switched to PMDD, they appear to have stopped growing. The amazon
sword has gone wild (even more than it was before) and the other plants
have shown little change. They grow slowly, but noting special.

I often see masses of bubbles, so I know there's photosynthesis going
on.

I started dosing with a few drops of PMDD every other day, but increased
this when nothing was happening. I now pour the stuff in, far more than
everyone seems to recommend. Algae is almost zero, unless I don't do
anything to the tank for two weeks, in which case there's a light coat
of it on the glass which cleans off easily.

Any ideas ? TIA

--
Alan Silver
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