# Is an HOB bad for Plants in low tech



## zfarsh (Apr 7, 2011)

Hi there,

My setup would be low tech lighting (shop lights) in a 75G tank with a Eheim 2217 as primary filter, and either an eheim 2215 or preferably an Aquaclean HOB 110 (or maybe a bit smaller). I will try to do medium to heavy planted, with low light plants (max medium light), such as hornworth, anubias, java moss, vals etc... (compatible with the fish bellow), playsand substrate

Why two filters, and specially the HOB as second? Because i will have very messy fish, ie: 6 fancy (slow) Goldfish, 2 Bristlenose Plecos, and either 3 dojos or 12 white cloud minnows or 6-8 fancy guppies. I have been told in forums this is not yet overstocked, specially if i do weekly 50% water changes. I may not get this many fish, but i want to plan for it in case this is reached. I may put smaller fish in a 10g tank eventually too..

Why my concern of the HOB, aquaclear 110? Because it puts alot of bubbles in the water, thus removing alot of CO2. (this is what i have read anyways.) I will add the general liquid fertilizers (not the one that has only CO2). My fish will be more important than the plants, but still, i care for both. Right now i have a small 10g with aquaclear 20, and without fertilizer, hornworth seems to be growing very well, and so is the java moss, but not the anubias does look as it is doing too well (maybe needs fertilizer). Instead of the HOB, i may be able to get a smaller size used canister for like 70$, so this is an option as well.

Pls let me know your thoughts on the HOB as secondary filter, or if it is even necessary, for the fish load mentioned?


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## bae (May 11, 2007)

First, goldfish will eat most plants eagerly. Note also that goldfish get large and are clumsy swimmers. They can mess up your aquascaping just by moving around. IIRC, One goldfish per 10 gallons is the recommended stocking level. This assumes, I suppose, that the goldfish are fancies, not the comets that can get to a foot (30cm) long. 

If you aren't injecting CO2, don't worry about water movement from filters removing it. From the point of view of the plants, they benefit from at least some water movement. In perfectly still water they will exhaust the nutrients from the film of water immediately adjacent to their surfaces, and have to 'wait' for more to diffuse in. But it doesn't take much water movement to avoid this.

In a low tech setup, you don't usually need to fertilize. The fish will do that for you. You probably don't need to worry about ammonia/nitrate, once the plants are growing. They will suck it up in competition with the filter, and their surfaces will be covered with beneficial bacteria and other microbes, too. You really only need one filter, IMO. If the problem is particulates in the water due to the goldfish, a HOB filter is easier to clean frequently. I use only sponges in mine -- my tanks all have plants so I really only need mechanical filtration, if any. 

I don't think you need 50% weekly water changes in a planted tank with this stocking level, assuming the plants are growing well, but I don't have any experience with goldfish. You could test for nitrates to see how big a change is necessary. But water changes are good, so if you don't mind making them, go ahead.

Note that the plants will only take up significant nutrients when they are growing -- the nutrients are incorporated into new tissue. Anubias and java moss don't grow very fast, so they don't take up as much as faster growing plants. Hornwort is fast growing and is great for this, as long as your goldfish don't eat it. Just let it float and pull some out when it gets thick. Duckweed is probably the best plant for quickly removing plant nutrients (aka pollutants), but goldfish love to eat it.

I hope this helps. Low tech planted tanks are actually healthier and easier to maintain than unplanted tanks, and much cheaper and less work than high tech tanks.


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## coldmantis (Apr 5, 2010)

hornwort, anubias, and maybe vals will be fine, java moss will be gone in 1 day.


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## carmenh (Dec 20, 2009)

It really does sound like you have 2 different tanks worth of ideas 

Everything except the goldfish would make for a great planted tank. The goldfish would do great (even on their own) in a larger tank, but good lighting and plants are probably a waste of time with them... And all the other fish don't need 75g. Have you considered getting, for example, 2 35g's or a 20g and a 50g? Rather than a 75? IMHO this would be a better choice... 

Also, I don't know goldfish, but I believe they prefer and are healthier in cooler temps, while the rest of those fish are tropical?


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## solarz (Aug 31, 2010)

carmenh said:


> It really does sound like you have 2 different tanks worth of ideas
> 
> Everything except the goldfish would make for a great planted tank. The goldfish would do great (even on their own) in a larger tank, but good lighting and plants are probably a waste of time with them... And all the other fish don't need 75g. Have you considered getting, for example, 2 35g's or a 20g and a 50g? Rather than a 75? IMHO this would be a better choice...
> 
> Also, I don't know goldfish, but I believe they prefer and are healthier in cooler temps, while the rest of those fish are tropical?


White cloud minnows are cold water as well, and guppies should be fine at room temperature. Don't know about the plecos and dojos though. Like others said, one just needs to select compatible plants for gold fish.


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## carmenh (Dec 20, 2009)

My bad  Should have done some reading before posting... I guess all these fish can survive cooler temps, with the possible exception of the pleco, depending on where you look. 
LOL I still think 2 separate tanks would be nicer, but that's strictly my opinion 



solarz said:


> White cloud minnows are cold water as well, and guppies should be fine at room temperature. Don't know about the plecos and dojos though. Like others said, one just needs to select compatible plants for gold fish.


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## qwerty (Dec 15, 2009)

My understanding is that in a naturally balanced tank without CO2 injection, the dissolved CO2 will be at equilibrium with the atmospheric CO2, since there isn't a constant input of CO2 into the water (ok, there is a bit of a contribution from fish respiration, decomposing organics, etc). So basically surface turbulence doesn't really make a _huge_ difference.

Whereas in a CO2 injected tank you're trying to shift the balance in favour of the dissolved CO2, so surface turbulence will become more problematic.

That's just my understanding. I try not to speak with too much authority on such topics.


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## laurahmm (Apr 1, 2010)

I've had goldfish and plants in the past. Just to let you know, your goldfish will uproot all plants that are stem cuttings. If they have good roots to hold them in place that will be fine... but the stem cuttings are a pain to constantly replant. I eventually gave up on those and pulled them out of my goldfish tank.


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