High nitrates from water change neglect. What to do?

Ok I’ve never heard this: low ph bacteria or high ph bacteria. I’ve read that in low ph ammonia becomes harmless and cycles stop or slow down. Nothing to eat. Fish live because they’ve adapted to the water.
Sparky did you ever change the substrate or vacume it out? What happened to the gouramies? Looks like you’ve got 20+ Young angels. So I’m guessing your feeding them a lot. A jumbo sponge would only work if you were changing 50% water daily. Again your overstocked so you need to overfilter. Look on eBay for a odyssea 250 internal filter. This filter is a power head with 2 sponges. Picks up lots of much. Clean the sponges at water changes and it’s a great filter.

 

With a large bioload like you have with the angels, I would suggest that you have a minimum of two filters. Even three filters would not be overkill. Any combination of sponge, HOB, and canister would work as long as they are large enough for the tank size. I would use filters rated for 100-125 gallon tanks rather than ones rated for a 75 gallon tank.

With that kind of bioload, your filters are going to need cleaning regularly. When you clean filters, you always lose a portion of your beneficial bacteria. The colonies will recover, but with as much waste as you have in that tank, you want as little disruption in the biofilter as possible. If you have multiple filters, you can clean one each time you do a water change and let the others do their job.

I would also suggest putting a prefilter sponge on the intake of your filters. The sponge will trap a lot of the larger debris before it enters the main filter. Beneficial bacteria will grow in the sponge as well. It is a lot easier cleaning the prefilter sponge than it is cleaning the main filter.

Another thing you might want to consider is a UV sterilizer. They help prevent algae and bacterial blooms. Some filters come with a sterilizer built in. You can also get separate sterilizers such as the Green Killing Machine. If you get a GKM, I would suggest getting the
24 watt unit. That will knock out your bacterial bloom in a few days. Then you can put it on a timer to run a few hours a day to keep the water clear.

 

You know what your doing SparkyJones continue on with the slow and steady approach.

 

Just a new update. I've got a pretty severe diatom bloom that's been going on since the last post. The GH has gone down to like my other tanks, KH is coming up and PH is definitely coming up. I'm at a solid 6.4 now.

The problem, nitrites. It's sitting around 1ppm nitrites which isn't bad necessarily, the ammonia isn't hitting at all and nitrates building as usual, but I can't currently run a zero on nitrites.

I'm assuming the colony is catching up in this category. Also thinking because it was so low pH for so long I do have low pH nitrifiers specialized for the 5pH or lower range. From studies I've been reading, at low pH (4-5 range) those Ammonia Oxidizing Bacteria "AOB" can convert ammonium straight to nitrate at a rate of 94% leaving just a small amount of nitrates to be dealt with by Nitrate Oxidizing Bacteria "NOB".

I'm still low pH enough to have ammonium as the vast majority, but I'm short on NOB as the AOB is adjusting to the change over to higher pH and higher pH range AOBs are populating and taking over again, causing this nitrite spike from the gap in ability which at low pH would have been a 0.01ml -0.10 nitrite reading that wouldn't even show up on a nitrite test.

All in all I have to test and watch the nitrites and WC as necessary but not overdo it and end up raising the pH further which will unlock more ammonia. As it gets closer to my taps pH 7.6.

I'm in a pickle here I think and going to have to carefully walk this nitrite line for a month or two, and do water changes to reduce the nitrates that build, but not so much change it pushes the pH up further. 1ppm nitrates isn't a big deal. A little stressing, but I have to watch it from going up to 2-3-4-5 where it's getting dangerous to deadly. And on the other side I have to do water changes to remove nitrates because my stocking puts on like 100 nitrates a week.

I think I have a good handle on this, it's been a long road to recovery and looks like a couple month longer, where I have to be really attentive and do the bare minimum that is necessary to keep it safe for the fish.
I have a feeling the diatoms are exploiting the nitrites and why the bloom is severe, but they are what's keeping the nitrites around 1ppm.
They will die off at some point when the colony of new AOB and NOB bacteria builds up and takes over, then the diatom die off and become nitrates also.
So this was March, with full blown Old Tank Syndrome.



I did lose the two kissing gouramis, but they were 15 years old and one of them nosedived and died right in from of me, I'm fairly confident it was natural causes and a heart attack. The other passed 3 months later. I moved the two blue gourami to another tank by themselves, they are also kind of old, 5 or 6 years, but didn't want them with the angels anymore. Evidence.




This is now. November and 8 months of water changes later, nearing the end, colony transitioning for the higher pH and diatoms doing the rebalancing and taking up the slack for the bacteria colony. I think that's what's happening.


This is where I'm the most worried about a crash but I think if I monitor and do just what's necessary on a day to day basis, it sorts itself out in the next month or so, then I can bring the pH back up to my tap water completely and it's fully recovered.

 

New year, New update and and interesting development.
Parameters currently are
1dGH
1dKH
pH 6.4
0 ammonia
0 nitrite
Under 10 nitrate.

I haven't done a water change in 3 weeks. The diatom bloom is unbelievably out of hand and running since late october when the pH came up past 6.0.



I noticed less nitrates at first, then
Last week's test I had 25-50ppm nitrates which was odd since the tank builds 100+ nitrates every week. I decided to let it ride.
This week it's at 10 nitrates, thats less than 1 day buildup.

I don't have live plants or anything that gets rid of nitrates currently besides waterchanging...

My current theory is the diatom bloom is consuming near all of the nitrates now and burned through the phosphates and probably whatever there was for silicates and now nearing exhausting the resources to where it all dies off and settles, at least I'm hoping that happens. This cloud is unbelievable, but besides being ugly to look at, the fish are fine and active and doing really well. The water still smells "earthy" like outside after a short rain. Everything seems good.

I haven't been water changing because of the bloom and feeling if I let it run its course its going to fall into place and it seems to be working out so far.

 

The fish police are coming for you.

Thanks for the update, good luck.

 

OTS is fully recovered it only took a year of water changes to do it safely, and in that time I raised angels from juveniles to adults in this tank.
All parameters are now in line with my tapwater, and the diatom bloom is finally subsiding after 3 months of it.

.

If I had to do it all over again I would have moved the fish and water to a tote and drip acclimated them and done a 100% water change rather than do it the slow and safe way which burned through a ton of water. Either the diatoms are tearing up the nitrates or now that the aquarium is back in line I'm water changing to a point that the nitrates aren't exceeding 10ppm anymore. Not sure which, maybe a combination of both.

 

OTS is fully recovered it only took a year of water changes to do it safely, and in that time I raised angels from juveniles to adults in this tank.
All parameters are now in line with my tapwater, and the diatom bloom is finally subsiding after 3 months of it.
View attachment 872530.

If I had to do it all over again I would have moved the fish and water to a tote and drip acclimated them and done a 100% water change rather than do it the slow and safe way which burned through a ton of water. Either the diatoms are tearing up the nitrates or now that the aquarium is back in line I'm water changing to a point that the nitrates aren't exceeding 10ppm anymore. Not sure which, maybe a combination of both.

Your angels are stunning SparkyJones !! Wow what a ride you’ve had with your aquarium, I wasn’t on the forum when you started this thread, but appreciate the info you’ve shared through your updates

 

Going to be the last update on this thread because its done and im where i want it to be. The OTS is recovered completely, the diatom bloom is about finished and clearing, and for some reason, my nitrates are just basically gone. I'm staying at like 10-15 nitrates a week now and can go 2 weeks before just feeling like i should do a water change so i dont get neglectful again. Not sure what's causing the nitrates to disappear (there should be more each week) or if it's going to drop off and start stacking up again, but I'll take it while it lasts!
The angels are now 1 year old, birthday was valentines day, so they are all matured, all males, and all getting along great, nobody is getting injured or nipped.


Mission Accomplished!