# What is a good density of planting to aim for in a NPT?



## helenf (Mar 24, 2008)

I have at first assumed that "the more plants the better" would hold. But I think in my oldest NPT, the little 5 gallon one, I am hitting the limits, if not already past them, for how much plant is actually healthy to have in the tank.

The more plants, the more they block each other's light. They also take up space and they reduce the (already small) currents in the tank, limiting the extent to which nutrients disperse around the tank, and reducing the effective removal of those nutrients. I think there must be a limit beyond which it simply isn't helpful to have more plants in a tank.

Here are photos of my 5 gallon (planted with various hygros, crypt, ambulia, milfoil, anubias nana and duckweed, fauna is male guppies, an apple snail and shrimp):









And the 10 gallon (planted with various hygros, a crypt, java moss, elodea densa, duckweed, fauna is spotted blue-eyes, corys, shrimp):









Would you say either of these is overplanted currently?

I personally think that the 5 gallon (first picture) probably is. I need to do some pruning on it, and have a think about which of the many plants in there I really want in there and growing, and which could do with being removed altogether, now that the tank is set up.

I'm not so sure about the 10 gallon, but I do notice that most of the hygros are growing quite straggly as they reach for the top, and they are certainly getting up there fast - I'm trimming them often so far. I would like to get more bushy growth around the bottom of the tank and have less competition for light at the top, but not sure how to achieve this.

I would welcome any comments that anybody has.


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## cs_gardener (Apr 28, 2006)

I think you're right that the first tank is overgrown. It's not so much the number of plants but the mass. The plants need to have enough room to continue growing and they've pretty much filled all available space. So it's time to cut them back and thin them out so that they can resume good growth again. 

I don't think the second tank is overplanted so much as it needs to be trimmed and have enough space between the stems so that light can reach the bottom. Since the bottoms are looking straggly I'd cut the stems off at or just below the level of the substrate (this will avoid stirring up the soil and the stem may regrow from the base but will most likely rot in the substrate providing nutrients for the replanted stems), remove some from the bottom of the stem and then replant the tops leaving enough room between each stem so that the leaves of adjacent stems aren't overlapping each other completely. You can trim the stems regularly to increase the branching and bushiness. I usually let the plant grow to the surface then cut about a fourth to a third of the way up the stem the first time and then further up each time until it's time to replant. I'd do only a bit of the stems at a time rather than the whole tank at once so not all plants are recovering and getting reestablished at the same time. You might also need to keep the top of the tank less covered with floaters if your stems are stretching for the light and the bottoms are losing leaves. Do you have sunlight that hits the tank at all? I can usually avoid the problem of ratty bases if there is even a bit of time when the tank gets sun or at least bright, indirect light from a window.


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## 01krisp10 (Feb 18, 2007)

I agree with Catherine, when a tank gets that amount of plant matter things start to slow down and algae starts appearing (speaking from experience, I've made most of the mistakes now, just waiting for the next few  ) and the bases of the plants start decaying. 

Another thing she mentioned that is crucial is triming only a bit at a time. Everytime I've done a major prune back of several plants the tank would always take a dive and algae would appear, seeing a theme yet? 

Awesome tanks, look like very happy homes.


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## dwalstad (Apr 14, 2006)

Beautiful tanks! You should be very pleased. 

I agree that the 5 gal needs a gentle trim. I wouldn't remove more than one-fourth of the biomass.


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## helenf (Mar 24, 2008)

Thanks for the advice, everyone.

I did some trimming of both tanks last night. It is hard to only trim a small amount at a time!

In the 10 gallon I mainly trimmed long hygro stems into multiple smaller hygro stems, and replanted nearly everything, aiming for a bushier effect. Not sure if it has worked yet.










In the 5 gallon I removed 2-3 stems that were growing sideways along the top of the tank, leaving more light and space for other things to grow. I'm pretty sure it was the right thing to do for this tank, and I'm now wondering whether it will help with the small algae problem I have with this tank, or whether it will make things worse.










The goldfish in my other tank are enjoying munching on some of the trimmings from the 5-gallon - stems of wisteria (hygro difformis) and suchlike never go to waste entirely in this house, though lots of them end up as goldfish fodder...


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## cs_gardener (Apr 28, 2006)

I think you've done well to trim and replant in the 10. You still have most of the plant mass and more light is reaching further down in the tank than before.

Your plants were probably a bit stressed in the 5 since they were so crowded. I think that they should do better since you've given them more growing room.


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## 01krisp10 (Feb 18, 2007)

Excellent trim job, very nice. May I ask what the bubbles are in the 10g tank in the rear left? Just curious because it could be removing co2 from the tank... sorry if I'm just seeing things.


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## helenf (Mar 24, 2008)

01krisp10 said:


> Excellent trim job, very nice. May I ask what the bubbles are in the 10g tank in the rear left? Just curious because it could be removing co2 from the tank... sorry if I'm just seeing things.


Thanks 

The airstone is there in the 10 gallon because I seem to have a problem (again) with persistent trace nitrite in that tank. I had this in the 5 gallon initially, and in fact is has come back there too in recent weeks. I don't understand whether it is the result of overfeeding or some bacterial action, but the airstone does seem to reduce the problem, so leaving that on until it goes away entirely, at which point I will remove the airstone.

It is always just a trace of nitrite, making the test look darker blue than the sky-blue "0 nitrite" colour. Never any ammonia, low or 0 nitrate. If anyone has suggestions to why this is occurring I would welcome them. I've pretty much decided to live with it for a few weeks or months and see whether it goes away on its own, since my previous strategy of doing water changes hasn't helped at all, as far as I can tell. Currently I'm trying only feeding the tanks in the mornings, which means that the plants have light with which to process the ammonia produced by the food, which might mean that less ammonia is consumed by bacteria which might mean there is less nitrite produced in the tanks. If that is the cause of the problem. Results are inconclusive so far. It is annoying me and I am worried it might be harming the fish too.


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## DataGuru (Mar 11, 2005)

I have surface agitation happening in some of my NPTs because if I don't, fish are piping in the mornings.

I usually pull and prune plants monthly in my NPTs. If I didn't, there'd be no room for critters! LOL


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