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Discussion Starter · #1 ·
Hi all, I've lurked here a fair amount but I've got a couple of things that have me scratching my head, so here's my first post. I'll start off with loads of detail and then try to summarize at the end. Feel free to read the end first and go back to the paragraphs for more detail. Tank details at the end

My two questions are 1: why isn't my Vallisneria doing anything and 2: I've got high nitrates and low fish load, ferts?

Background, feel free to skip this paragraph

I tend to research things to death before doing them. I have a tank about a decade old. It's been many years since I've put any new fish in and got them to stop breeding (livebearers) and it's actually reached a point where most of my fish have died off of old age. I let the stock dwindle and now it's very lightly stocked. I've always thought planted tanks looked great so I decided to try my hand at plants before upping the stock again. So when I revamped my plumbing 6 months ago I also put some soil in. I had sand before and mixed some gravel in.

The plant bit

I bought Aponogeton (3 rizomes in 1) from a LFS and planted it. It sat for about 3 days and then exploded, they're huge now, massive success, and they've slowed down as they've gotten big. Then about 3-ish months ago (before armageddon) I bought some Vallisneria, Dwarf Saggitaria, and C. Wendtii (red) online. I got Aquarium Co-OP's Easy Green fertilizer at the same time. The C. Wendtii is doing great, no melt, and I know it's a slow grower so I'm quite happy with its development. The Dwarf Saggitaria has seen a little growth, it melted back a little but once I pruned back the dying bits it looks like it's doing ok. The Val is what's confusing me.

The Vallesneria bit

Everyone always talks about Vallesneria being explosive and having to hack out gobs of it to keep it from overthrowing their tank. My Val hasn't done anything in 3ish months. It died back a little when I first got it, I pruned away those bits, and then it's just sat there. It's not growing, it's not dying, it looks healthy, it's just not really doing anything. So my question is, what can I do to help it get going? My tank is low-tech, I'm not gonna fuss about with CO2 right now, I know that would help, but is there anything else? Has anyone else had experience with this? My substrate is mostly sand, could that be a factor? Is there another parameter I should be testing that relates to this?

The nitrate bit

Now, my tank is very lightly stocked. Two tetras, a cory cat, and a snail should not be mucking up a 45 gal much at all. All Ammonia and Nitrites 0 and 0 ppm. Nitrates, close to 100 ppm. I do monthly 50% changes, one of my ultimate goals is to create a balanced ecosystem for a low-maintenance tank. That's one of my motivations for planting things like Val that are supposed to uptake a lot of nitrates, but as mentioned earlier, my Val isn't growing, so the nitrates aren't going anywhere. The Easy Green fertilizer that I'm using seems to be primarily nitrogen, so I'm wondering if that could be a source of the high nitrates. I also forget what the soil is, that could be a source as well, but it never rose above 20 ppm when I only had the soil in there. I only used the Easy Green for a few weeks and then backed off as nitrates rose. So my question is: do you think I should not use a water column fert? Do ferts high in nitrogen lead to high nitrates if over-dosed? That would make sense to me, but there might be a chemistry element I'm missing. I think most of my plants are primarily root feeders anyways and I do have soil down there somewhere.

The summary bit

So I have Vallisneria that isn't growing or dying after 3 months and wondering why. I have high nitrates in a lightly stocked tank and I'm wondering if ferts are to blame or if I'm missing something.

Tank: 45 Gal
Substrate: mostly sand with some soil and gravel mixed
Carbon: no CO2 and no intention of injecting at this time
Light: homemade LED, fairly bright but no hard data on it
Lid: polycarbonate

2 bloodskirt tetras
1 cory cat
1 unidentified hitchhiking snail

3 aponogeton (growing great, explosively at first, slowed down now)
2 Cryptocoryne wendtii (no melt, perky)
2 Dwarf Saggitaria (died back a little, growing very slowly now)
2 Vallisneria (one with a runner and a little baby plant attached, came like that, died back at first, then hasn't done anything for 2 months)

Ammonia: 0
Nitrites: 0
Nitrates: 80-100
PH: don't remember, I'll get back with that in the morning

505 Posts
Kh/gh would be a better thing to know than ph. Not that it's that imparative. I've grown Val's in soft water with success.

My first thought was any plant tabs?

I know you said there was some soil being used. Did you mix in osmocote?

If not, and even if you did, maybe look into getting some. I've run Val's in straight aquarium gravel but with the addition of plant tabs (I used Seachem but that's because it's what I had on hand). They would always respond well to knew additions.

As for the use of Easy Green. In your case it's not really needed. Maybe as a once a week or once a water change thing. Root tabs is more what you need (unless soil has ferts in it).

I would, however, do enough water changes to get the nitrates down a bit. Although nitrates from ferts are no where near as bad as nitrates from dissolved organics, mulm, etc.

Sent from my Pixel 3 XL using Tapatalk

2,064 Posts
Same here: the val nana plants have been just sitting there for several months now (six?). Ditto the shoreweed. 6 dGH, 5 dKH, 68-72F; root tabs plus daily Flourish Comp solution & KH2PO4 solution, plus Salty Shrimp GH + KH added to the change water weekly.

Even in a high tech tank, I never had any real success with vals. They just sit there at best, melting mid-blade and detaching at worst.
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