inconsistent plant growth behaviour between tanks

Anyone know what I;'m having the following problem, I have two new
Juwel tanks, a RIO 125 and a RIO 180. Both have been planted with
similar plants, eg some amazons, some grasses etc, both have some
bogwood and both have a single co2 generator - Hagen A-7690 - and I
have used plant food regularly with both. Both have 4in airstones at
the back of the tank.

However, one tanks is thriving (Rio180), so much so that I have had to
reduce the lighting period in order to cut down the growth and the
algae, while the other is only just about holding its own.

The only difference between the two tanks is that the rio125 is
overfiltered quite a lot (if's full of platies) with an extra fluval 3
plus, while the rio 180 which has mainly tetras has only got an extra
fluval 2 plus, as they don't crap so much.

Brian

"Spindoctor" wrote in message
...
Anyone know what I;'m having the following problem, I have two new
Juwel tanks, a RIO 125 and a RIO 180. Both have been planted with
similar plants, eg some amazons, some grasses etc, both have some
bogwood and both have a single co2 generator - Hagen A-7690 - and I
have used plant food regularly with both. Both have 4in airstones at
the back of the tank.

However, one tanks is thriving (Rio180), so much so that I have had to
reduce the lighting period in order to cut down the growth and the
algae, while the other is only just about holding its own.

The only difference between the two tanks is that the rio125 is
overfiltered quite a lot (if's full of platies) with an extra fluval 3
plus, while the rio 180 which has mainly tetras has only got an extra
fluval 2 plus, as they don't crap so much.

Brian

The overfiltered Rio125 would (in theory) cause the injected CO2 to
dissipate out faster (which is good for the platys who like higher pH
anyways), so your plants would have less in the way of carbon to feed on.
The extra filtration surface area in the Rio125 would (in theory) provide
a better environment to have more nitrifying bacteria working faster
(removing ammonia and nitrites which are basically plant food). Those
are the only two factors I see affecting you, but I've had nearly
identical tanks yield different plant growth, so sometimes it's more a
case of which missing nutrient created the constraint, and the nature of
the constrain affects how the plant reacts. You might also be using
different foods, which contain trace elements which might satisfy a
constraint (there be many variables down this road ;~).

NetMax