What should my nitrates be at in a planted tank? Problems with levels and filters

[Maria Ashton]

I ask because in my discus tank nitrates fluctuate between 10 - 25, obviously the latter is high. I have another non discus community tank which is normally around 15-20 but the other day nitrates shot up to 100, I did a 75% wc and had a look at the filter, changed the top sponge pad and am now watching it closely, I do not know why it shot up.

In my discus community tank my XL filter is barely working so we added another filter to work and in a day we plan to take out the XL and work out what is wrong, however... nitrites were at 0.5 last night - is this the new filter which has been running since Friday night alongside the normal one, or is it a complete failure on the part of the XL. We did a wc last night and have another planned for this morning but I wanted any advice/ thoughts from you guys

Maria

[Chad Hughes]

Maria,

Your filter will not remove nitrates. In fact, your filter produces nitrates by breaking down ammonia to nitrite to nitrate. If your filter was failing, I would think that you'd see ammonia and/or nitrite issues. If your filter is extremely dirty, you could see nitrate spikes.

Now, for the planted part. How densly is your tank planted? Your plants should readily consume nitrate. Most planted tanks have nitrate of zero and frequently require dosing of nitrate in the form of a fertilizer (potassium phosphate) to keep the plants healthy. Are you using plant fertilizers? If so, what do you use? What kind of substrate are you using? Mulm in the substrate can lead to nitrate spikes if heavily polluted. Is your planted tank thriving? Do you have algae in excess? A plant nutrient inbalance will keep plants from thriving and they will not readily consume nitrate. Are you supplying a source of CO2?

Sorry for all the questions. Just trying to get a feel for what you have going on.

Regards,

[lipadj46]

The reason why heavily planted tanks can have high nitrates is that the plants hide waste and it accumulates and causes problems. I have a high tech tank where no matter how high the light or CO2 if I do not meticulously clean at the roots my nitrates would be obscenely high.

[Maria Ashton]

Chad - I appreciate the help.

It was very densely planted but is less so now, will try and upload a photo although not having much luck with that on here.
The plants are thriving, I have removed some.
I did have a problem with cyanobacteria but its not such a problem now - dont know if that is related.
I think there might be something in the substrate which is Manado by JBL, it was put in about three months ago when I got the tank, (tank and occupants second hand).
Normal algae is kept in check by three small plecos who go to town from time to time.
I do have some brown algae but its going
No CO2 but I was considering it...

Also considering a Philips aquarium purifier which works with ozone to break down organic matter and reduce nitrates.

I do 30 - 50% wc every 2 to 3 days
117G or 450L tank
13 discus of various sizes, none more than 5 inches or less than 3
2 baby angelfish
18 carinal neons
3 small plecos
3 German rams
2 electric blue rams
8 corydora

I have a feeling you are going to say less fish....

Appreciate the help
Maria

[ericatdallas]

lipadj46 is right... if you aren't able to get into all parts of your planted tank, it can store a lot of gunk. Worse, if you do decide to clean your gravel or move decorations and plants, you risk releasing hydrogen sulfide and other waste which could cause an ammonia spike.

Another question is, what are your nitrates going into the tank? Your nitrates are pretty high ... When I had a planted tank, I used to dose 5-10ppm and the water the next day was 0 ppm. High lights, CO2, and fast growing plants help a lot...

Also, are you sure your test is working correctly?

You could always send your water to an aquarium-hydroponics (aquaponics) setup :)

I could be wrong, but I don't think cyanobacteria will increase nitrates. I'm pretty sure they're actually helping lower it. In fact, you probably had the problem because there was so much available in terms of nutrients.

So taking a step back, regardless of tank type, you have to ask why you have such high nitrates.

1) If it's from the source you need an RO filter.
2) If it's not, then are you overfeeding?
3) I don't know what other stuff you have in there (inanimate decorations) but what is your effective volume? 450L might be your actual, but how much of that is used up by gravel, rocks, plants, background, etc? You may have an effective volume of 300L and your tank is definitely way overstocked by those standards.
4) Also, how often do you clean your filters? What kind do you have? Filters can become nitrate generators if the media is covered in organics.

Also consider using Seachem Excel or glutaraldehyde (as directed) to solve your BBA. BBA is a symptom of low CO2.

[Chad Hughes]

Maria,

No lecture on the stocking. I'm an overstocker myself and it appears that your water change routine is pretty good unless you are feeding very heavily. The heavier the feeding the more water chagnes.

I am leaning heavily towards your substrate. I took a quick look of the product on line and it claims to "prevent the growth of algae by absorbing excess nutrients". That is a bit scary in my opinion. I prefer to use inert substrates. Anything that absorbs requires changing from time to time. How long has that substrate been in there? It also looks a bit bulky, like gravel. Is that true or is the picture I saw not accurate? I prefer sand as it doesn't allow debris to settle below the substrate. Everything stays on top and can easily be removed. You can layer plant substrate under sand if you prefer.

All the best!

[Maria Ashton]

Thanks everyone, based on what you have all said I think its both the substrate and the main filter - the last time we cleaned it the media was covered in snails, have been scared to interfere with it too much since as we knocked the bio filter out and had a nightmare for 10 days.

I might be overfeeding but there are never left overs in the tank, the discus have frozen bloodworm, mysis or beef heart 3 to 4 times a day. The other fish have granules and algae wafers once a day.

Maria

[ericatdallas]

I would be surprised if you knocked the bio-filter in a planted tank completely out. The planted tank (substrate, plants, etc) are bio-filters in their own right. Just use dechlorinated water to wash the media out...

I would probably avoid the BH in a planted tank (speaking as someone that used to). JMO.

I noticed my water quality improved when I didn't and there are numerous threads from other people backing that. If you do, you might consider doing it an hour before WCs. The BH breaks apart and finds places to hide.

[Maria Ashton]

Eric - yes I have noticed that and more so with my own BH mix rather than the shop bought. What do you feed? I find frozen mysis or brine shrimp does the same thing. For some reason they always hunt out the last of the frozen blood worms so there are rarely any left.

[ericatdallas]

Grrr... just wrote a long post and it disappeared when my internet connection died as I submitted :(

Anyway, ... yeah, eliminate BH helps, maybe try a sinking pellet food, do massive WC and vacuum of the gravel daily. I did 1/3 per day on a rotating schedule but you could also try 1/2 every other day if you don't want to do WC every day. I've seen strategies for increasing flow in areas where food gets caught, but i didn't do this. I also bought a siphon vac that had a narrow tube so I could reach more ... but the drain was slower. Freeze dried bloodworms or blackworms in a feeder cone might help too, but not sure since I haven't done this before. Reducing feeding mass but increasing feeding frequency might work as well.

I ended up throwing my plants and gravel away because I got tired of it.

I'll probably do it again and if I were to do it differently I would plan a way so that everything is more accessible and reduce crevices that stuff can hide in (i.e. caves). I might also choose plants that's aren't so dense or have very extensive root networks. Not sure...

[greengreen84]

+1 on the freeze dried black worms or any freezed discus food that floats on the surface of the water, Most of the time the food doesn't get a chance to fall to the ground so keeping the ground clean gets alot easyier but you can also get mysis shrimp freezed dried also brine shrimp freeze dried and to top it off beef heart flakes if you can try and aviod using frozen food that fall to the ground.

You could also try some red cherry shrimps to cut down left over food, start with about 20 to 30 their a great clean up crew as long as you have some bushy plants or foreground plants some where to hide overwise they can become a quick meal.

But shrimps can move pretty fast when a discus is near faster than a discus that is lol also some shrimp can be dam cheeky and flick dirt in their face of the discus if they try to eat them that is lol

also be carefull with stocking discus in a planted tank as the plants take up swimming space and it reduces the amount of discus you can stock i have a pair of adult discus in a 60 gallon planted tank but it's packed with plants, i would put one more in but their breeding and would have a domistic every time the lay eggs with the outsider lol, but good luck with the tank hope all goes well for you.

[Maria Ashton]

Thanks, I seem to have two pairs but the dominant ones win when it comes to breeding, thus far the eggs have always been eaten. I am in the process of cleaning them up before allowing them a tank on their own to breed. I do think overcrowding might be a problem and if its not now it will be soon, there is plenty of swimming space but when the couple try and breed they force everyone into a corner.