Slowing the growth on a CO/2 setup

[suep]

I've had a 46 gallon bowfront set up since December, pressurized CO2, 96 watts of power compact lights. Fancy guppies, cardinals, hatchet fish, a pearl guorami. Swords, lilies, wisteria, too many plants to remember. I'll post a link to some pictures but these are a couple months old and the scape has changed. (I pulled the large swords out before they took over the entire tank. ) The tank is doing really well. A bit too well, in fact. The weekly water changes are fairly easy but I'm finding the trimming to be a bit of a pain every week. I'd like to slow the growth down some, if I can do so without hurting anything or causing serious algae.

I'm assuming that if I cut the light to one bulb at a time instead of two, and reduce the amount of KNO3, etc I'm dosing, that the growth will moderate without a lot of problems. Am I right? Is there anything I should be watching for, or should be doing instead of or in addition to?

Thanks! This site has been a wonderful help this past year!

http://www.cowgirlcoder.com/pictures/2008-03-19 002 fresh small.jpg

 

[Tom Barr]

There are multiple methods to reduce growth.
I'm never sure why folks always head to ferts for this, as it makes the least sense in terms of goals.

I think the easiest method for most is to chose slower growing species, Crypts, ferns, mosses, lower growing species...........

Add more rock, wood etc so you do not have to spend the time cutting plants.


Reduce the light, might be tougher for some, but certainly a lot easier if you can use say several T5's vs a single source(use only one of the 2 bulbs at a time), or raise it up higher to reduce intensity, place screen between the tank and light source(pretty effective really) etc.

Light is the wisest method to reduce rates of growth.
It's easy once set, it's very stable, no need to test or worry about getting too low etc, "when did I last dose?" etc.

CO2 will also slow the rates of growth down and going non CO2 is a very good option given many folk's goals, you might want to look more into this one.

I think if you run 1 bulb for 4 hours, then the other for another 4 hours, that will slow things down a bit.

Look for species that are not a PITA to trim, or need weekly or every 2 week trimming etc.

Most of the easy to grow plant you have on the list are very fast growers, now keep a few(not many, but a few), and this will reduce the work load, also, learning how to trim and topping can make things much easier/faster/less labor also.

With less uptake due to lower light, you will not need as much cO2/KNO3 etc, but that does not mean adding that amount will do harm as much either.
You can also slow growth with low PO4, which is likely wiser than using NO3.

But you can add less(and more current etc).

Regards,
Tom Barr

 

[suep]

Thanks, Tom!

So, I'm only using one bulb at a time, and if I add ferts (KNO3, Iron, Traces) twice a week instead of three times, and basically skip the KH2PO4, I should be good? I do tend to feed my fish quite well, so they'll get some that way.

I am changing the plants out but I hate to pull out all of the wisteria. I love the bright green and the guppy fry love it when it's thick. It may come to that, though. I had an epic battle but I seem to have gotten all of the duckweed, finally!

I like the CO2, it may be superstition, but I think it helps cut the algae.

 

[Tom Barr]

Oh I hate duckweed much more than algae..........algae I can kill.

I think your plan sounds good. Stick with the KH2PO4 for now though.
Use 1/2 the light and alternate those bulbs, one on at time only and then only for 4-4.5 hours at most(then you switch to the other bulb).

By using both of them at different times, you will still get a good spread on light at different angles, and the bulbs are pretty intense.

2x a week ferts is fine, make sure to dose mid week though. Also, you can still dose more frequently with the traces if you wish.

You may want to use screen if this is too much light still.
Regards,
Tom Barr

 

[suep]

OK, great! I'll holler if I have any problems but this sounds like it'll work.

The duckweed was an epic battle, but I think I've won. The sad thing is, I added it deliberately to help screen extra light. And it does look good outside, in the pond.