Blolded section does seem to imply the comment I made about you not thinking them reliable IMO....
then you either dont know how to read, or your reading comprehension is poor. im not sure which, but either way, this has been explained to you numerous times now.
Be careful with Ad-homen comments. They can be agaist forum rules, if seen as hateful, discriminate e.t.c
The origional context did appear to infer that you thought the Rena exturnal would not be capable of lasting as long as your livestock. I have re-read it a few times to be clear, and that is deffinately being implyed, intentionally or otherwise. Either your posting style is unclear and you may whish to look at that to avoid confusion in the future, or there was an intentional ineration there (if inferation is a word
).
sorry, it was a typo. it was the 203 i was referring to
also, when buying a filter second hand there is more to worry about then simply how long it was in operation. without having actually been there, you have no idea what kind of condition the filter is truly in. its admirable that you believe this "respected member" has taken care of the filter as it should have been, and may well have, but you can never be sure when buying second hand.
I know age isn't the main issue. The main one is maintanance, more to the point, if the seals were loobed, impeller kept clean and free, preventing it running dry where ever possible e.t.c
Well a mech filter does not remove the dirt by itself does it? It's still in the system, just in the filter media. It will still leach out the mank untill removed, 6 months later in the case of a canister when you clean it, so yes, IMO mech is just asthetic unless you are cleaning your filter on an exteramly regular bases
BAHAHAHAHAH
are you saying you dont clean your filters? or only every 6 mo?
BAHAHAHHAHAHAHAHHAHA
again, i hope youre not serious
i dont even think this needs to be readdressed.
Something entertaining about the fact you don't have to clean a canister filter out regularly? My TT runs on a 335l planted discus tank that gets at least 4 heavy feeds a day, and does not suffer from a loss of flow for 6 months at a time. It collects the dirt all right, the tank runs with sand so dirt is always obviouse when present, and the sand looks spotless most of the time
You find where it all went when you open the filter though
The general rule with any filter is not to touch unless flow rates are realy dropping off. You can keep a filter too clean
So, yes, that was a serious comment. IME, mech filtration is only asthetic
Right, well, removing half as much over twice as many passes, lets look at this in detail. For simplicity's sake, lets assume the canisters is just managing to remove it all in one pass, so the HOB is removing half.
Can at 1 turnovers per hour, 100% removed per pass
on first pass; 100% removed
HOB at 2 turnovers per hour, 50% removed per pass
on first pass; 50% removed
on second pass; 75% removed (50% of 50% = 25%, so 25% of the origional was removed second pass, making 75% in total
)
i think you need to check your math again. 50% + 50% = 100% here in the US. the second pass would be the same amount as the first pass. not 50% of the ammonia in the filter, rather 50% of the ammonia in the tank. thus, 2 passes doing the same as 1 of the canister.
So, to summarise
Mech = HOB, without a doubt.
Bio = depends on the system (while a tetratech will not do the same as an aquaclear. the same goes for basic canisters vs. updated ones)
Price = HOB wins
Mech is won with modifyed HOB's or running a powerhead along side as you yourself state, when compaired to an out of the box can. Give the privelage of mods to the can also, or the powerhead option, and the can still wins
So, a corrected summary of your chart to allow for either modifying both, or neither gives
Mech = can
Bio = still debating
Price - HOB
Now, why two passes, when removing half of the ammonia per pass, are equal to 75%. Same as per waterchanges. You remove half the waste on the first pass, so lets say 1ppm goes in;
1/2 = 0.5 out
Now, second pass removes another half
0.5/2 = 0.25 out
So, as a persantage, thats 0.25/1 * 100 = 25% of the origional amount, so 75% was removed. The dispute is because you are assuming that when half is removed per pass, you can add the halves together. This is incorrect. You are removing
half of what goes in. We are also assuming that no ammonia is added between passes here also, reality is obviously different.
Since we are still debating Mech, lets look at it again to see why it's still debatable. You have to modify the filter or double up or install a powerhead as you say. You can do this with the can and improve it's mech filtration also. If you placed the spraybar of the can directly above the substrate so it kicked all the much up into the water colum, and modifyed your HOB to take water from the opposit end of the tank, you would likely find the can out-performs the HOB still, as the can still has the better circulation pattern in the tank
this would be true if modifying it, or adding the powerhead, was necessary. however it isnt. as mentioned after your first post in this thread, modification is an additional option to further increase performance, but is not necessary out of the box. with the HOB putting out double the flowrate of the can (maybe more depending on the canister), it is absolutely doing a better job of mech filtration. even with a canister, there will be dead spots in the tank where debris settles to the bottom, unfortunately, unlike the HOB mentioned, it does not have the additional sucking power to make up for those dead spots. so, no, the can does not provide anywhere close to the amount of mechanical filtration as the HOB.
hang on a second here, you are shurely contradicting yourself again
Right, the can pushes a better flow throughout the whole tank, so keeping all the particles in suspension longer than the HOB with localised curculation spots mainly, yes? Great , we agree on this for the second time
So, with the HOB, half of the tank is a dead spot, where as with the can, only a few areas are. Therefore, while the HOB does clean locally far better than the can, overall, it's preforming worse.
The comment you make about Tetratec's being as bad as Fluvals, where did I make it? What I said about the life of the seal on the TT compaired to a Fluval was assuming the filters were being poorly maintained, not under propper running conditions
Maintain both well, and you'll find that the Tetratec should be more reliable
All the best
Rabbut
