JennDFK

We have a 29 gallon hex tank with an Aquaclear 50 filter and a history of high nitrate levels. I added some salvaged intake tubes to get closer to the bottom of this rather tall tank. We do water changes every couple of weeks and often have nitrate levels between 20-40. Any ideas for a good, compact filter that will clean up the water better? I know that I should probably change the water weekly, but reality suggests that will not always happen. Are canisters worth the extra expense?

iloveengl

It's the water changes, not the filter type, that lowers nitrates. I use a 5g bucket and a gravel vac to do twelve gallons once a week for my 55g. You could get away with just one 5g bucket once per week if you're not overstocked. If you can't do buckets, you might want to check out those python vacs that just hook up to the sink. But once you get on a schedule, it's easier to do.

Edit: Lots of live plants also lowers nitrates. That's the extent of my plant knowledge though.

ccb04

As mentioned ... it's primarily water changes that will keep nitrate levels at bay.

Not that it's a factor in your case, but filter media maintenance is another component ... rinsing media like sponges in used tank water, changing floss, etc. Any filter type can raise nitrates if the media isn't cleaned/changed often enough ... including canisters.

If you wanted to improve filtration (not necessarily nitrate removal) ... prehaps go up to a filter that gives you 300 GPH or so (10x turnover).

Toddnbecka

Some fast-growing plants like Najas (assuming you have sufficient lighting) would reduce the nitrates between partial changes. If you don't have much light duckweed would also work, but it tends to get "eaten" by HOB intakes. A sponge prefilter would help with that issue.

JennDFK

We do 10 gallon water changes every two weeks. We try to do weekly changes... but with a busy family life sometimes we don't always get to them every weekend. We replaced our carbon with an extra sponge for the filter and we rinse them out every water change and do a more extensive cleaning every other water change.

We have a large number of plants... several vals, 2 varieties of java fern, 2 anubius, two water onions, a sword and this bulb plant that is a super fast grower. We also have duck weed in the tank that hitched a ride with our water onion...but I scoop it out often so that it doesn't block out light.

Our thought was that since the tank is so deep that maybe we weren't getting good filtration with the aquaclear by taxing it a bit extra with the longer intake tube... but if extra filtration is not the answer to our nitrate problem... then I guess our only option is to do the weekly changes... and try to do a better job of cleaning up the substrate... although that is tough in such a heavily planted hex.

We really thought that the extra planting would go a long way to solve our problem. We have more than tripled the number of plants in the tank in the past three months... but so far they don't seem to be doing much for the levels.

ccb04

Jenn, what are you using to test for nitrates? If strips, prehaps you're not getting an accurate reading? I mention this because I'm also a bit surprised the plants haven't helped control nitrate levels.

Filtration can be a contributing difference if it's not removing enough debris mechanically or if it's not cleaned enough. It's just not the biggest difference ... that of course is the aforementioned water changes. With HOB filters in particular ... you should shoot for 8-10x turnover (I prefer 10x or better). It sounds like you're doing enough filter maintenance like rinsing the sponges, etc. Prehaps the AC50 isn't enough for the deep tank and bio load.

You could add the AC50 to your 55g along with your biowheel 350 ... that would give you 550 GPH on your 55g (for a perfect 10x turnover). Then you could add an AC70 (300 GPH) ... Emperor 280 (280 GPH) ... etc. to the 29g if you wanted to go HOB.

If you would prefer to try a canister for the 29g ... Petsmart sells the Eheim Classic 2213 for $69 online, which is an excellent price. And right now, they have $6 S&H on orders over $60. The spray bar in your hex could be positioned vertically so as to both fit the tank and so it doesn't drive off CO2 for the plants. The Eheim Classic has been around for 25+ years ... so the design has proven more than reliable and is consistently one of the highest rated canisters I've found.

JennDFK

I'm using the API test kit for all my testing... I'm not overstocked either.