Filtration And Overtstocking

[wildechild_01]

Im just curious if anyone has any experiance or recommendations here. I have a tank that is fully stocked, according to AquaAdvisor site, mostly its full due to selection of some large fish... specifically the Discuss. Given their size at times the tank looks decidedly empty so i was thinking of Overstocking and adding some Med sized fish, not sure what yet.. but something around the size of Swordtails, to fill out the look of the aquarium. Obviously more filtration will be needed so i guess my question is... How effective is adding more filtration when overstocking a Tank? The Discus can be a little particular with water quality so i dont want to go Overboard and Throw off quality. I Figure overstocked would require more and/or larger Water changes to remove solid waste that settles on the bottom but other than that..... anyway i am rambling now, so any advice or sugestions would be greatly appreciated.

 

[raptorrex]

Im just curious if anyone has any experiance or recommendations here. I have a tank that is fully stocked, according to AquaAdvisor site, mostly its full due to selection of some large fish... specifically the Discuss. Given their size at times the tank looks decidedly empty so i was thinking of Overstocking and adding some Med sized fish, not sure what yet.. but something around the size of Swordtails, to fill out the look of the aquarium. Obviously more filtration will be needed so i guess my question is... How effective is adding more filtration when overstocking a Tank? The Discus can be a little particular with water quality so i dont want to go Overboard and Throw off quality. I Figure overstocked would require more and/or larger Water changes to remove solid waste that settles on the bottom but other than that..... anyway i am rambling now, so any advice or sugestions would be greatly appreciated.

providing you have the media area, the filter will do fine. but water changes may become an hourly thing.

 

[ninjaseal]

Im just curious if anyone has any experiance or recommendations here. I have a tank that is fully stocked, according to AquaAdvisor site, mostly its full due to selection of some large fish... specifically the Discuss. Given their size at times the tank looks decidedly empty so i was thinking of Overstocking and adding some Med sized fish, not sure what yet.. but something around the size of Swordtails, to fill out the look of the aquarium. Obviously more filtration will be needed so i guess my question is... How effective is adding more filtration when overstocking a Tank? The Discus can be a little particular with water quality so i dont want to go Overboard and Throw off quality. I Figure overstocked would require more and/or larger Water changes to remove solid waste that settles on the bottom but other than that..... anyway i am rambling now, so any advice or sugestions would be greatly appreciated.

providing you have the media area, the filter will do fine. but water changes may become an hourly thing.

believe it or not it would be cheaper in the long run to get a bigger tank and it would be healthier for the fish..

cus think about it more water changes? if you dont set the temp rite for water changes.. all ur doing is shocking the fish.. you need a lot of patience with stuff like that..especially when u dont use hot water out the tap...so if you overstock make sure you get the right filtration and do water changes with the same temp out the bucket to the fish tank /based on your ammonia nitrate nitrite levels....

not saying you dont match the temp in water changes...but alot of people dont

btw nice tanks!! ya i think most definately you could add a few more critters in the 90

what kind of filtration do you have?

 

[raptorrex]

Im just curious if anyone has any experiance or recommendations here. I have a tank that is fully stocked, according to AquaAdvisor site, mostly its full due to selection of some large fish... specifically the Discuss. Given their size at times the tank looks decidedly empty so i was thinking of Overstocking and adding some Med sized fish, not sure what yet.. but something around the size of Swordtails, to fill out the look of the aquarium. Obviously more filtration will be needed so i guess my question is... How effective is adding more filtration when overstocking a Tank? The Discus can be a little particular with water quality so i dont want to go Overboard and Throw off quality. I Figure overstocked would require more and/or larger Water changes to remove solid waste that settles on the bottom but other than that..... anyway i am rambling now, so any advice or sugestions would be greatly appreciated.

providing you have the media area, the filter will do fine. but water changes may become an hourly thing.

believe it or not it would be cheaper in the long run to get a bigger tank and it would be healthier for the fish..

cus think about it more water changes? if you dont set the temp rite for water changes.. all ur doing is shocking the fish.. you need a lot of patience with stuff like that..especially when u dont use hot water out the tap...so if you overstock make sure you get the right filtration and do water changes with the same temp out the bucket to the fish tank /based on your ammonia nitrate nitrite levels....

not saying you dont match the temp in water changes...but alot of people dont

btw nice tanks!! ya i think most definately you could add a few more critters in the 90

what kind of filtration do you have?

I could not agree more. on the bigger tank thing.

I'm one who does not match temp. because there is no need (below 30%). you can use water from the "hot tap" too. i've heard the arguments against . but they don't stack up. not that i think there is anything wrong with boiling water to match temp, if you want too. but hot tap is fine. and there is no need in the first place.

 

[kelly528]

Filtration is effective (and necessary with overstocking) but only to a point. Remember, the bacteria housed n your filter media will only deal with ammonia and nitrites. So you need to overfilter to cope with the ammonia and nitrites and then do water changes to keep up with the nitrates.

 

[bitteraspects]

Added filtration is vital for "overstocked" tanks. and more so than that, you want efficient filtration.
Basically, what you're looking for is added bio media volume (to offset the added ammonia production in the tank), added turnover/circulation (to help remove the added solid waste from your water column), and if possible added water volume (to help stabilize water parameters between WC).

While a large canister can help with all of these things to some extent, your best bet is to add a wet/dry sump to your current filtration set up. It is by far the best solution to all the things above, and best part about it is, a DIY wet/dry sump is extremely cost efficiant. Also, because of the flexibility of this type of system (you can customize every aspect of the filter to fit your tank), you cam set up a relatively low flow system that will still give you the added water volume and media volume, without having such a strong current that it upsets delicate fish like your discus.

Now. as mentioned earlier, you will also need to up your WC frequency. Nitrate production will be higher than with a traditionally stocked tank. Keep your liquid test kit handy and check your water parameters daily for a few weeks intill you have a good idea of how often you need to do a PWC. personally, I do atleast 2 PWC a week on my overstocked tanks.
In addition to nitrate removal, WC serve a more important purpose in "overstocked" tanks, which is removal of GH hormone build up. This hormone is the cause of stunted growth.

Another thing you can look into is adding live plants or a FW refugium to the tank. or even better, an algae scrubber (or "turf scrubber"). These additions can also help keep the nitrate levels down dramatically. However, nothing replaces the need for a religious WC schedule.

 

[OldMan47]

It is time to get down to reality here Wildechild. There is no limit to the amount of stocking you can do on a tank if you are willing to do the needed water changes to keep up with the nitrate build in your tank. What does that mean to you? It means that if you can do the required frequent water changes you can go to any, that's right any, stock level that you wish. The bad part is very simple. No matter how much filtration you provide, the water must be changed often enough to keep poisons under control. Read that statement again. No matter how much filtration you have the chemistry of your tank will depend mostly on your water change amount and frequency. If you have the typical filtration on your tank, you have far more than enough biofiltration capacity to handle any reasonable stocking level. The limiting factor will become your willingness to do frequent and large water changes. You are the real limit to how many fish you can keep under normal circumstances. Where does that put you? In my own case, I have a few tanks that are grossly overstocked by traditional formulas but my fish in those tanks thrive because I recognize that they need frequent large water changes. On the other hand, an overstock based on simply a filtration increase is a disaster waiting to happen. Over filtration only works to remove solids from the tank's water, not the nitrogen that is a critical component of a cycled tank. That means that over-filtration does not help where it is really needed, in the biological response of the tank to a particular stock level.

 

[bitteraspects]

well said.

 

[wildechild_01]

Man oh Man am i glad i asked this question.. ha ha ha Score one for Forums and doing research. I am currently doing weekly water changes on the big tank and fairly small ones at that, usually only in the 15% range i would say. I do temp match the water on my changes. I was planning on waiting to do this and after the pointing out that the filter cant do everything and more frequent WC will be necessary i am definitely going to have to wait a bit... i am in school right now so 2-3 wc a week wouldn't be a big deal but when i head back to work i may be out of town some weeks... so will wait and see. As for the options given here i think my best bet may be the DIY Sump system, space becomes an issue if i go to a larger tank... unless i re-arrange the living room, and then where do i but the current tank... i guess i could move the 30g occupants into it.. ha ha ha... would you believe me if i told you my first tank was purchased back in October last year... oh man... anyway off toppic... Would the Sump option help with the WC frequency??? obviously adding more water would dilute the PPM readings, also would make water changes easier as can do everything in the sump i would think... provided it is large enough to account for the ammount of water change needed...

My tank is actually quite well planted. i will try to post a pic of it up here a little later so they help with the Nitrates...

but i am off to do my Electrician learnings..

Thanks for the Advice.

 

[bitteraspects]

the increased volume of the water column will help stabilize the parameters between WC, but unless you incorporate a FW refugium or algae scrubber , it wont really change your WC frequency much.

usually i just do WC from my sump. IME its a lot easier. you can also connect a quick drain on the sump (i have mine plumbed with a ball valve for easy opening)which will make it even faster.

 

[wildechild_01]

here is a picture of the tank i am talking about.

My tank

 

[andywg]

[...] an algae scrubber (or "turf scrubber"). These additions can also help keep the nitrate levels down dramatically. However, nothing replaces the need for a religious WC schedule.

In my experience, algae turf scrubbers are often used precisely to replace the need for a water change schedule.

In addition to nitrate removal, WC serve a more important purpose in "overstocked" tanks, which is removal of GH hormone build up. This hormone is the cause of stunted growth

I can't help but play devil's advocate here. Is there any actual evidence that stunted growth in good water conditions is actually bad? The only science I recall was something Bignose found stating that the internal organs of the fish were fine when dissected. Also, I seem to recall a debate in the scientific forum being fairly inconclusive as to whether there really was a growth inhibition hormone which is excreted by fish since they seem to respond to a number of different stimuli when it came to growth rates and sizes attained.

 

[OldMan47]

I am not aware of any real research on the hormone thing either Andy. It is an assumption that is fairly wide spread based on the benefits that people see from doing frequent water changes. There is plenty of empirical evidence that growth rates do respond to frequent water changes. The obvious next thing that happens is somebody hypothesizes on the reason and others do not notice that it is a mere hypothesis and take it as gospel. I am reminded of a time when everyone knew the world was flat too. At least I have read about it, I am not quite that old.

 

[bitteraspects]

I read a few studies on it a while back. I'm sure you can just as easily find the information.
I don't have them bookmarked a ymore, and as I'm posing from my blackberfy, I don't ha e full access to google scholar, but if you google "GH hormone, stunted growt, and carp, I'm sure you will turn up quite a few results.
There were studies in tropical fish as well, but it takes some digging to find them. However the studies on carp (and I believe, bluegolls) are readily availible online.

 

[andywg]

It would appear I am not as able to find them as you. I have checked my two ichthyology reference books I have as well as searched briefly on google scholar and the only references I can find to growth hormone concentrate on its effects on the changes in the physiology of fish (particularly osmoregulatory functions) and the fact that dosing with it causes fish to grow more rapidly and increase appetite, which appears to be the opposite of the point made above. Nothing I could find mentioned the excretion of a hormone which inhibited growth.

Anything you can dig up will be most welcome. Closest I can come is an old thread in the science forum.

As somewhat of an obiter dictum there is the fact that many freshwater fish farms operate on a closed loop system yet do not experience a drop in growth rates compared to open systems (as discussed in Nadav Shnel a,b, Yoram Barak a, Tamir Ezer b, Zaev Dafni b,Jaap van Rijn a, Design and performance of a zero-discharge tilapia recirculating system Aquacultural Engineering 26 (2002) 191–203)