More Powerful Filter

[MeganA]

I just got a new 30 gallon tank. It currently has a Aquatech 20-40 on it. When I use the ##150### calculator and add all the fish I currently have in in the tank it shows my filtration is at 106% but when I add the fish I plan to add to it to finish stocking it shows my filtration dropping to 70% which indicates I will need to get a better filter. My trouble is that when I look up some of the filters online and plug them into the calculator it shows me having to use a very powerful filter that would be designed for much larger tanks. I do not have enough length room in my hood to accommodate a filter that big. I am not sure I quite understand...Does anyone have any suggestions on what I should upgrade to?

 

[OldMan47]

Megan, the reason your post of that forum's name came up as unacceptable was that we reviewed the calculations and found that the model was too unreliable to allow people to link to it from here. What fish do you have, how big is your tank and what is your maintenance regime? Any stocking can be maintained in almost any tank with any filter if water changes are adjusted to accommodate the number of fish. More importantly, and a factor that place never considers correctly, is that the volume of a filter means a lot more to efficient conversion of ammonia than any flow reading at all. It is one of the reasons they are no longer allowed to solicit business here.
The Aquatech 20-40 is designed to deal with a typical fish load for a tank up to about 40 gallons. Unless you are grossly overstocked it will be just fine as a biological filter. More filtration will never allow a higher stocking level. That will be determined by the willingness you have for water changes.

Here is why.

Each fish contributes x amount of ammonia to a tank's environment. That ammonia is converted to nitrates, eventually, in a ratio of 3.6 ppm of nitrates for each 1 ppm of ammonia produced. You do a water change whenever the concentration of nitrates in the tank water approaches 20 ppm above your tap water to reduce the value. Depending on how big the water changes are, that may be 2 days or 2 weeks between water changes. It could be even longer if you are very lightly populated. Now, in this description, did I ever refer to filter flow or filter size? Yet all of the pertinent factors are being addressed.

It is a mistake that the author of that calculator fails to recognize. He has fallen into the trap of a non-fish keeper who only knows what he reads from relative beginners in the hobby, many of whom believe that filter size and fish load are somehow related. Sorry. Any reasonable filter size in any reasonably stocked tank has far more capacity than is required to merely process the ammonia through to nitrates. The person who produced that calculator has my admiration, as a database designer myself, in designing a well put together database, but unfortunately he has no understanding of fish and their biological processes.

 

[MeganA]

OK well that is very good to know because it was contradicting all the other things that I had read I am glad that you clarified that for me. I am well under stocked in my tank. I have 3 platy, 3 mollies, 4 corys, and a albino long finned bristlenose in a 30 gallon tank. I have spent a lot of time on this forum and have read a bunch of your responses to peoples posts and I thank you for putting your knowledge out there for all of us newbies! I really enjoy fish keeping and it is always nice to talk to someone that I KNOW is knowledgeable. Sometimes you get so many different responses from people and it can get confusing )I do have one more question for you though since I have your attention...I currently have a heater that does not have a thermostat on it for me to set the temp, I have put a in water thermometer and a stick on tank thermometer (one on each side of the tank)but I cant seem to get my temp any higher than 79F. I made a huge mistake and bought the bristlenose on impulse and he infected my tank with ich and now I am trying to fix that with raising my water temp and then adding salt. I just cant get it higher than 80 it is a 100 watt do I need a new heater? Am I treating the ich the best way or do you have any better suggestions for me to try?

 

[OldMan47]

Megan, that is exactly why I try to give you that bit of added knowledge that ties things together. Otherwise it would simply be my word against theirs. Why would you trust me over them? There is no such thing as an authority, at least in my mind, for these things. The best we can ever do is try to give a new person a chance to truly understand why we think what we think. If you choose to agree with what we try to teach, you are really depending on your own judgement, not some abstract authority figure. I think that is far superior in almost any circumstance. It means that you know why you think a particular thing is right.

 

[MeganA]

Based on all the information I have read your information has been very consistent. Not from this forum though I think there are a lot of knowledgeable people on this forum. But I get a lot of bad information from my pet stores and other people. When reading your post you always explain things very thoroughly! Much appreciated!

 

[OldMan47]

Pet shops have a very different priority to ours. We gain nothing by having you follow our recommendations except some sense of satisfaction of having helped you do things right? OK now what does a pet shop gain by you believing them? Do they get to sell you more stuff at a profit? I think that most fish forums are better advisers than your LFS, but that is merely my judgement. You must make your own.