My Ludwigia has gone spindly. It's not light (4 wpg), so I think my KH has gotten too high. KH tested at 13 in the tank and 5 out of the tap. I've pulled the Coral out of the filter after my water change today. I think my GH is around 10 or lower, but it's hard to tell, since my test kit is fading.

CO2 is about 45, other things more or less EI.

Swords don't seem bothered by the conditions BTW.

I grow Ludwigia Repens at higher KH than 13 and it's fine. As a matter of fact I grow everything in hard tap water and it seems I have less problems than ppl with RO water

If you like pictures of L repens growing on limestone, as in pure limestone look at this from limestone spring fed river.

Seems pretty happy to me in hard water stable:-)


Regards,
Tom Barr

How are you measuring CO2? Many of us used to think we had high levels of CO2 in the water by measuring the KH and pH of the tank water. But, we didn't have it. If you use a drop checker you can be almost sure of the measurement.

LOL, You guys are full of good news. My fish have been off too (One Tetra with a bent spine), so I was sure it was the KH/GH.

The ol' KH/PH trick.

I've been reading your Drop Checker thread with great interest though. It's next on my list of things to build.

kH is allways lower then gH...Check your tests...

No, if someone uses a water softener, their KH will be extremely high(the salt does not exchange HCO3, only Ca/Mg) and the GH will be very low.
In general though, the GH is is higher than KH in most cases.

GH high= fine okay for every plant I've grown(300 or so species at least).
KH is fine up to about 5 or so, for all plants, but over this general range, some do poorer, you can grow them, but they do better and are easier to grow at low KH's.

So the Ca is not so much an issue as is the KH.
I've found this plant growing in near freezing temps, in road side ditches all over Florida, in rock hard limestone rivers/spring(very common), in blackwater ditch pools, pH about 4.7 to 5.0 and no GH/KH.

So I'd say it is a very tough, wide ranging habitat easy to grow weed.
At least that's what the natural habitat would suggest


Regards,
Tom Barr