Nitrates again

Since I started filtering my tap water I have been gradually increasing my planting. I won't go so far as calling it heavily planted but I have started adding liquid ferts.

Today I returned from a 2 week holiday and the first thing I did was check the nitrates as there have been no water changes for 2 weeks. The fish were also fed less in my absence. I asked the house sitters to feed every other day and made them count pellets or wafers as they don't keep fish and I know how easy it is to overfeed .

I was rather pleasantly surprised to discover that my nitrates had dropped from 15 to 5 ppm in those 2 weeks. (Ammonia and nitrite still zero so nothing dodgy going on ). The water sprite actually didn't look great (I have some planted and lots floating) and some nasty looking algae on the floating plants (see pic). No algae further down in the tank so assume there is too much light at the top and possibly food trapped on the leaves as I usually move these out of the way to feed. The Anubias and java ferns actually had a lot more new growth than I expected. I also added more plants today as I had some left over from planting the nano (vallisneria spiralis and elodea).

So

1. Should I keep filtering the tap water or just plant more
2. Any suggestions on getting rid of the algae - I have just rinsed the floating plants in tap water and put them back, along with a 50% water change and ferts.

Green filamentous algae loves light and nutrients. It could be from the liquid fertiliser you started adding to the tank. Some of the plant guys might be able to offer more info but I just pull the stuff out and throw it on the garden.

Try using unfiltered water for a month and see how the nitrates go with the plants you have. If it starts to go up rapidly then cut back on feeding, use filtered water again, or add more plants

With the exception of the water sprite, most of your [slow growing] plants do little to lower nitrates. It's likely that the very sparse feeding (and the water sprite) kept nitrates low.
I forget the exact nitrate value of your source water, but I'm not sure I would use it unfiltered (I don't use mine w/o filtering). You could give it a try, but watch tank nitrates closely.
I'm not sure why you're seeing algae on your floating water sprite. I'd suggest backing off on both the photo period (or light intensity with a shade cloth screen) and the ferts. We want the plants to grow...but we also want them to scavenge the water to remove nutrients (aka pollution). In many cases, in a low tech tank, plants can do just fine with fish/plant waste and only slight addition of micronutrients. I know of some that manage low tech planted tanks with little or no added fertilizers.

AbbeysDad said:

With the exception of the water sprite, most of your [slow growing] plants do little to lower nitrates.

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I do have rather a lot of it in the hood, together with frogbit.

Now the jetlag is almost gone I suspect its not such a mystery after all. As ever its all about balance. Just before I went on holiday I thinned the frogbit massively to throw it into the garden pond. I reduced my lighting by an hour a day to compensate for the loss of shade but I suspect it wasn't enough. If I had been here I would have noticed and adapted accordingly. That would explain the growth spurt of the slower growing plants in the bottom.

It also explains why the water sprite went brown. According to my friend google it does this whenever you change lighting (more or less) and will recover. It also has a lot of new healthy growth, both on the floating and planted plants.

I'd forgotten how quickly elodea grows. Planted 2 good sized bunches yesterday and I swear they are over an inch taller today . I also floated loads of cuttings. Hopefully the balance will be restored in the next week or two

Two water changes later and all is good with the world again. I manually removed a lot of it but now its actively dying.

Working theory is that its a combination of organic waste due to missing 2 weeks water changes and elevated nitrates. My Pozzani filter cartridge was exhausted but for the 2 changes I have gone back to putting nitrate free water back into the tank.

I promised to update on my efforts to recharge the cartrige in a brine solution so here goes.

It failed. Haven't lost anything I didn't have so not too disappointed.

seangee said:

I promised to update on my efforts to recharge the cartrige in a brine solution so here goes.

It failed. Haven't lost anything I didn't have so not too disappointed.

Click to expand...

Were you able to add [super] non-iodized salt water into (and fill) the filter and let it soak for an extended period, then drain and repeat the process one more time?

Soaked for 2 weeks. Never tried repeating the process. FIf you think it makes a difference I'll give it a go next time.

You'll recall my converted API Tap Water Filter filled with API Nitra-Zorb.
I hope I don't jinx myself, but I have used this same resin to produce over 2200 gallons of nitrate free water so far! I get about 250 gallons between recharges.
To recharge I premix a super (non-iodized) salt solution with warm/hot tap water. I keep a gallon on hand all the time. I call it 'super salt water' because the amount of salt reaches the point where no more salt can dissolve. So it's real salty!
I drain the filter of fresh water and fill with the salt water,,,actually letting some pass through. Full of salt water, I let it sit for several hours, sometimes even overnight. I let this drain and then fill again with new salt water. This will then stay in the filter until the next time (as much as a week) I need to filter water.
I make sure I flush with enough fresh water to ensure all of the slat water is removed before collecting.
Hope this helps.
Perhaps your filter is using some different resin/method to adsorb nitrates OR the filter cartridge does not lend it self well to injecting a salt solution???
Worst case is if the filter cartridges are not too expensive, you still have a viable means to filter nitrates out of your source water!
Good luck.