I have 13 golds in a 120 gallon and they are all relatively small, from 2 inchs up to one that is 4 inchs. (I'm not counting the tail fins, are we supposed to when measuring.
I have no problem with any parameters except nitrates. I have been changing water, 50% each week. I've had to increase to twice a week. The nitrates jump up to 40plus almost overnight. When I had tropicals in there, I had as many as 60 fish and never had nitrates approach 20.
Perhaps I'm feeding too much? I know the gold fish body mass far exceeds the individual body mass of the tropicals I had.
I can't imagine how many times I will be changing water when these puppies grow. I wish I could filter out nitrates. I may have to get another tank in the future.

It does sound like you are feeding heavily..... How low do you get the nitrates when you change? In theory, if you have nitrates at 40ppm before a change, change 50%, you will get nitrates at 20ppm..... Is that what your tests done post change show?

It is possible that you have more than 40ppm - those red colors can be decieving. I have found that in tanks that are heavily fed, you can get something I call nitrate creep. Each week I change out enough to lower it, but not enough to take out a week's worth - and thusly each week, the nitrate climbs a bit more.

Try testing before and after the change. Then, if needed, do a 75% or more change and feed less heavily....



I change out the water when it is needed. Some tanks need it every 3 days. Others can go a week. Some need 33%, others need 75%.....

Welcome to goldfish keeping.

I have 4 in my 55 gallon, which is borderline for me, because I don't have 10X filtration. I'm running 460 right now. I have a 280 Emporer on the way to replace a Fin 60 that came with my setup, so soon I'll have over 10X. Then I am betting that my Nitrates will be able to keep under 10, instead of sitting at 20 until 90% weekly water changes.

Did you tell us what kind of filtration you have?

I have four fish in a 55 gallon, but they are single-tails, which should have 20 gallons each, and they are huge, ranging from 6-12 inches or so.

I only have 680 gallons per hour filtration since one of my filters broke, so I have to really work on the nitrates too.

I removed the gravel and am bare bottom now, which helped a little bit. If you have gravel and want to keep it, make sure you are vaccuuming it really well each time you change out the water.

Have you looked at your filter padding or sponges? If they are all gunky with crud, you might try this, although read hte whole thing first. I have found that when my filter pads and sponges get all gunky, that rinsing them out with hot tap water until they look clean again helps a lot. However, I have three media baskets packed full of ceramic cylinders, plus 3 bio-wheels, so I have tons of good bacteria without the filter padding and sponges. If you did not know, rinsing anything in the filter with tap water (which is chlorinated) kills the good bacteria, so you only want to do this if you have a strong cycle (seems like you do) and have other things for the good bacteria to grow on besides the sponges and/or padding. If you don't have other media in your filters you can still remove the sponge and padding and rinse them either in dirty tank water removed from the tank, or in dechlorinated tap water, swirl them around in a bucklet of it and squeeze out any sponges repeatedly. You are squeezing them in dirty water but at least the solid gunk gets out. Worth a try in the ongoing nitrates battle!

Good luck. :-)

Makes me want to do a water change immediately jen! I cannot keep my nitrates down either and think I have nitrate creep in 2 tanks. It seems the longer established your bio media becomes
the more worrying nitrates are. My newly seeded tanks always have low nitrates. Some fish are very hardy but others will suffer from the high levels. Doc I would suggest trying a 80 or 90% change if its weekly-as daryl says you have to work out what w/c percentage works for your tank and feeding regime. That needs adjusting as the fish grow too.

I am not sure, but arent live plants suppose to help out with nitrates..I have a problem with nitrates all the time also...I didnt used to when I lived in a ifferent area, I will test my tap water as son as I finish this posting and see what I got going on from the tap.

my tap water comes out as the following:
pH - 6.4
Ammonia - 0
Nitrite - 0
Nitrate - 0
Ironically, after my water is aged 24+ hours, my pH is 7.4..is that normal?

That ph thing is pretty normal. It has something to do with the lack of aeration when it comes out of the tap so I just put mine in a tub with an airstone and age it overnight and it goes from 7.8 ph to 8.4.

Has anyone considered a "Nitrate Filter"? I've read about them and they sound like they would work. I'm interested if anyone has one and what they think of it.

I forget the name at the moment, but I have one of those bag filter thingy's that is supposed to absorb the extra Nitrates/Nitrites, but I don't think it does much.

Is that what you're asking?

a heavily planted tank will have zero nitrates
large amounts of algae also drastically reduce nitrates, the thick green hair algae is the best nitrate reducer, either way you need mega lighting to grow the stuff

also filtering through plants (veggie filter) will reduce nitrates to zero.
veggie filters are ugly as sin to look at, but they do wonders on nitrates
veggie filters are home made

How does one build a veggie filter?

veggie filters were designed for ponds but can be used on large home aquariums

if your handy you can do it..me myself i cant even build with lego's

heres a few links...
this one someone describes how they made it
http://www.thekrib.com/Filters/plant.html#0

this is the origional pond way, i have seen people use this method, putting the container on a very strong shelf or table next to the aquarium. keep in mind you need a plant grow light above the veggie filter to keep the plants well illuminated, a pond pump and flexible pond tubing
http://www.bonniesplants.com/how_to/veggiefilter.html


what holds nitrates more than anything is the filter cartridge, floss, sponges, bio balls etc. all those things over time become nitrate factories

floss or some kind of floss mat is your best bet since its easily tossed out every 2 weeks so nitrates dont have a chance to build up
bare bottom tanks are also a good choice

I have 5 tanks, I try to do one per day that way they are all changed every 5 days. sometimes I take a break for a day or so but no one goes more than a week without a change. I do deep water changes, I leave the fish just enough to swim in, and replace the rest. I clean the bottoms while I change the water.

each tank gets a total teardown and filter cleaning once a month or when the flow slows down. If the bottom has alot of debri, I will take the fish out and tear it down to clean it.

It's not too time consuming this way. Sometimes I do two smaller tanks in one day especially if I know my work schedule is going to make it hard for me to get it done.