Minsc

The biggest challenge I've found in keeping healthy planted tanks is the proper adjustment of water flow and CO2. There seems to be a thousand variables, mist vs. reactor, spray bar vs. lily pipe, level of surface disruption, etc...

The deeper the tank front to back, the more difficult it becomes to get water flow to all the plants, without completely blowing them away in other areas.
I've tried numerous methods myself, split returns, misting, multiple pumps, and it seems I can never dial it in quite right. Once the tank fills in to a certain point, plant health starts declining.

So, how does ever one else set up their CO2/filtration system in a tank 18+ inches deep? Let's hear about your systems! I want pictures too

TAB

full lenght spray bars, generally facing down.

davemonkey

My tank is narrow, but I increase circulation with a powerhead. Hydor Koralia do a good job also with less force (larger output). If you have your CO2 set-up so as to get it mixed in your water flow, then good circulation should take care of the rest.

-Dave

Minsc

Koralias are really nice! I'm desperately trying to avoid adding (expensive)clutter to the tank at the moment, but I may break down some day.

Minsc

I have a full length spray bar in a smaller tank, and I love it!
What do you mean by facing down? Where are the holes pointed?

houseofcards

I do the same thing. That's what I'm using on my 72g right now. I have the spray bar mounted to the left side and the holes are positioned at about a 45 degree angle downward. I'm using just a Eheim 2215 and I can clearly see the plants swaying on the far end. I also get plenty of co2 there as well. I've never used powerheads I just don't like any add'l equipment.

niko

Funny thing you ask about flow. We seldom discus flow in planted tanks but it has a profound effect on the plant's health.

To reiterate a few well known things:

1. All canister filters are rated wrong. If a filter says it moves 350 GPH that does not mean it actually does it 2-3 feet above the canister housing. Often the flow is cut 3 times. L shaped elbows, ingenious in-line reactors, and so on really reduce the flow.

2. Plants have a strange, magical, ability to block flow. VERY efficient. A spraybar placed on the bottom of a bare tank may move the entire body of water in a circular manner. But when the plants are in only a few inches of water in front of the spraybar actually move.

3. Differences in temperature due to uneven flow are very common. Even in a 55 gal. planted tank with a Fluval 404 (300 or so gph filter). Nutrients and waste products are not distributed/dissipated properly.

4. In the course of a week the filter manages to get clogged at least a little bit. Often the flow is visibly reduced, but usually it appears fine. Either way - the flow on Day 1 is not the same as the flow on Day 4. Is that a bid deal though? If you think that the plants adapt and it's all fine and dandy because you rinse your filter material every so often then good luck. Very few filter materials are engineered properly - to not clog easily. Most will "help" you and get clogged pretty fast. They will clean the water faster because of the progressive reduction of the orifices through which the water has to flow. You end up with a pretty clean water, reduced flow, reduced biofiltration and all that good stuff. Rinsing the sponges in aquarium water seems like a good idea. But it's not - disturbing the organisms that form the biofilter is the most persistent of the many idiotic habits we have in this hobby.

So after all of the above back to the original question. The most flexible way to add flow to a tank (big or not) is with small powerheads. Place them wherever you find they work best. If the tank is heavily planted you can hide them. Move them as you find appropriate if you find that the water movement is not good enough. Don't think that if flow is needed in a certain direction pointing the outlfow that way will always work. You may find that the best powerhead positioning is not very intuitive. And don't forget to remove the sponges in the small powerheads (see #4 above).

Or you can build an elaborate undergravel piping and hope you got all bases covered.

--Nikolay

nvision

i too have tried many methods in a deep tank, 36x24x24", including multiple filters with split outlets, koralias, powerheads, etc., and the full-length spray bar has worked best for me as well. i attach mine in the back, about 1-2" below water line aimed about 5 degress down. it's powered by a large powerhead misting with a co2 line, and the sweeping trail of tiny bubbles rolling across the tank is a great way to gauge flow characteristics. it's the most uniform and efficient method i've seen thus far.

jasa73

I use hydor Koralias, i love them. I'm setting up a taller tank myself and will be pointing the return hose vertically on one side.

Coralite

Might I recommend that you try to employ a gyre in your aquarium to get all of the water moving together. This article has everything you need to know about mass water movement.