RedDelPaPa

Hi all.

New to this forum, but not so new to the world of fishkeeping and growing aquatic plants.

I just wanted to share my successful and unsucessful experiences in growing aquatic plants.

Over the years, I believe I have discovered a link between heavy biological filtering and unsuccesful attempts at growing aquatic plants. For years, I have kept Hornwort, Val, Sag, and Hygro Polysperma. All these plants mentioned seem to do quite well in my aquariums, and my Dad's alike. However, if introduced into an identical setup(lighting, fish, substrate), only with an undergravel filter, plant growth almost completely stops, and in some cases, dies completely. I have heard stories that the cause is the UGF is keeping the plant roots from absorbing nutrients, and trace elements from the gravel. I don't think I buy this theory because of the negative affects it has on the floating plants as well. Like the Hornwort.

Over the years I have come to strongly believe that the plants require small amounts of ammonia in the water in order to grow. Possibly even Nitrite's too. After all, garden fertilizers contain ammonia. And I think heavy bio filtering takes away the ammonia before the plants get a chance to use it. Thus causing stunting or eventual death of the plant(s).

What are your thoughts on this?

Thanks for any info,
Nate

Laith

I haven't seen a UGF here in any stores in, let's see... in fact, I can't remember ever seeing one anywhere in the region.

Ammonia tends to trigger algae outbreaks. We normally give our plants their Nitrogen through the addition of KNO3 to the tank (Nitrates).

In a way you're right in that if the plants have no source of Nitrogen, they will do very badly. Once again, that's why we add KNO3 to planted tanks.

Biological filtering is less important in a heavily planted tank which is why when I set up a tank heavily planted from day one I never get a cycle.

Laith

And welcome to APC!

RedDelPaPa

Hello, and thanks for the welcome.

Can anyone explain then what is happening to the water chemistry in a tank with heavy bio filtering, that would cause stunting or death of aquarium plants?

All I can figure is, the heavy biological filtering is taking away some sort of nutrient(s) that the plants need in order to grow.

I believe that nitrate deficiency would never be a problem in a tank with a heavy to moderate fish stock. Especially in a tank with heavy bio filtering. Nitrate supply in a setup like that should be through the roof.

SnakeIce

The Undergravel filter only tank has enough nutrients, but the flow of water in the tank isn't enough to disturb the boundary layer that surrounds solid surfaces and thus your plants use up all the nutrients in the water close to them. They then don't grow even though there is nutrients in the general tank water.

Raul-7

It is true that bio-filters produce a lot of NO3, but remember they do this by converting ammonia to nitirite and finally nitrite to nitrate. Plants can use all three as a source for nitrogen, but ammonia is the preffered nitrogen source. Thus the plants will compete with the bacteria for ammonia, plants will eventually get the upperhand and the bacteria colony will begin to die back.

Plants alone can keep ammonia under control, but for this to happen you need well-established, healthy growing plants. The reason why we get an algae break when we setup a new tank is because the plants aren't well-established, and algae end up getting the upperhand during the break-in period. Algae diminshes once plants flourish.

I'm not saying you don't need one, we all need them as backup incase our plants aren't doing great. You just don't need something like a FBF, Wet-Dry, etc. After all bacteria is everywhere in the tank, and plants aren't at all affected by that. In fact we need both, plants and bacteria, to sustain a healthy aquatic environment.

Phil Edwards

If you have a UGF in your tank I would recommend finding a powerhead small enough to fit on it and use that instead of an airstone/bubble-lift mechanism. Your filter plate and substrate should have trapped enough mulm to provide enough NO3 to the plants. Adding a powerhead to get good current will only help deliver that to the rest of the system.

Best,
Phil

Simpte 27

I don't see the direct relation between the heavy bio-filtering and poor plant growth. The bacterial colony that dwells in the gravel does get first crack at the ammonia and nitrites but their finished product is a macro fert (NO3). I would tend to think that the problem is something else. Could be the UGF is stunting the roots but I couldn't tell you for sure. Plants don't need ammonia. If they did why don't we dose it?

RedDelPaPa

Well, you do, on your lawn. And a plant is a plant. Probably not in the aquarium because it's toxic to the fish. And I don't think the UGF is stunting any roots on the hornwort, but it does still affect it negatively.

I'm telling ya, they do need ammonia. And like the gentlemen above said about ammonia being the preferred nitrogen source, I believe it. It makes perfect sense from the experiences I've had. From the 15 years of trial and error between both my Dad and I, there is something to this. Something that I don't think is completely understood yet. Even by so called "experts".

I'm telling you. For example, my Dad has a nice 30gal tank with a moderate fish load. It has an undergravel filter in place, but not in service. The tank is well planted with atleast half being occupied by many beautiful bunches of Giant Hygrophila, and a nice sized bunch of floating hornwort. Once a month, he has to throw away a big mess of hornwort, and trim 6 or 7" off the Giant Hygrophila. So I would say the plants are doing well. Nice and pretty green. Not a dead or decaying leaf on them. Fire up the UGF, and within a week or 2, all the plants stunt and starting turning yellow. Even beginning to rot away. Leave the UGF running long enough, and their won't be a living plant in the tank before long. We've seen this happen a half dozen times before.

So without a doubt, I'm pointing my finger at the extra bio filtering the UGF provides.

shalu

UGF is not more effecient biological filter than wet/dry, now is it? And I have no problem growing plants with a wet/dry filter with a sump.