TDI-line said:I think as long as you have a decent filter each end you will be ok.
Jeremy said:Don't mix up flow with filtration, the two are two different things.
You cannot over filter a tank but you can have too much flow for some plants.
Having said that, I would have no problems with ten times turnover in any planted tank.
Why go for four 2217s?
That means four plugs and eight pipes, and 2217s don't even prime.
Check the wattage as well, 4 x any external may cost you dear in electricity
I did a review of external filters and the Tetratec was one of the best. Loads of media, strong, but controllable flow and it primes in seconds.
Dave Spencer said:TDI-line said:I think as long as you have a decent filter each end you will be ok.
I pretty much agree with this. Having 100l/h of filtration at one end may not be as effective as having 300l/h at each end, in terms of movement of nutrients around the tank.
Jeremy said:You don't want a wet dry sump dude.
Another name for trickle filters is degassing towers.
If you opt for a sump, go for the freshwater version of the Ecosystem, with plants growing in the sump.
Underworld distribute freshwater Ecosystems in the UK.
I wouldn't even have wet/dry on marines.
It is an out of date method that produces nitrate.
If you seal your tower how does oxygen get in?
Also, when you so conveniently remove dirty mechanical media from a sump, all the gunk gets shot back into the main tank.
As we are on the subject of external freshwater filtering methods, a bead filter is a good option for large tanks.
Overflow boxes, homemade or otherwise are noisy and problematic. If you ever go for a sump, drill the tank and install a top and bottom scavenging weir.
No doubt sks will put me right.
A couple of points apart from the advantage/disadvantage of trickle filters - Having strong biological filtration is never, ever a bad thing. Ammonia uptake by plants, especially in a high light tank is not a prerequisite and should never be considered as "robbing" the plants of some vital function. Further, in the "ideal" scenario, the biological filters do all the ammonia conversion and the plants simply use the resultant nitrate. Since we are dosing relatively high concentrations of KNO3, ammonia availability is neither a desirable condition nor is it necessarily relevant as far as plant uptake. The presence of ammonia is heavily correlated to Algal proliferation and should be minimized as much as possible. This is why bigger filters filled with huge surface area biomedia should be a primary goal, especially in a big tank.
Secondly, most of what we consider "the good bacteria" thrive within an oxygen rich environment. These are referred to as aerobic bacteria. The bacteria which proliferate in oxygen poor environments are "anaerobic" bacteria and normally do bad things in our tanks. There is a symbiotic relationship therefore between the plants and the "good" bacteria in that oxygen production and ejection into the water column by plants during the photoperiod facilitates ammonia reduction by those bacteria. Ammonia reduction is a deterrent to the development of the algae which are a constant threat to the plants.
sks said:So, you are saying, to the effect (and correct me if I'm wrong), even if we are only using 10% of our biological filtering capacity of 4 large canister filters because the media it contains is SO high in surface area (Eheim Efisubstrat comes to mind), we have the added bonus of a lot of flow and mixing as well, and a LOT of capacity to spare (and grow more good bacteria should the need/load requires), and that can only be a good thing?
sks said:My way of looking at it is to provide sufficiently excessive biological filtration and let the cheap wave making powerheads do the rest. You now have the best of both worlds and use less expense. In the old days people were told not to run their bio towers with too much water flow since you could wash off the bacteria. I'm sure that there is some kind of relationship between contact time and ammonia conversion.