# Old Tank Syndrome



## coldmantis (Apr 5, 2010)

I don't see this talked about a lot on this forum so lets start a conversation about it. Who here has suffered or is currently suffering from OTS?

I'll start I have a 29g fully planted thats been running for at least 4-5 years. It's set up for my parents and contains plants I no longer want in my Display tank or trimmings and fish I don't want. It has eco-complete that is at least 3+ years old, since it's a fully planted tank I cannot vacuum the substrate because you can't see the substrate with all the carpeting plants.

I treat this tank like all my other tanks it gets a %50 water change once a month and the Eheim 2217 filter is fully taken apart hoses and all and is thoroughly cleaned about 4 times a year. For the longest time I only had two fish in there a full size male albino pleco which I mangage to breed from a regular brown pleco and a full size upside catfish that is about 7-8 years old, it also has hudnreds of MTS snails. I feed the tank 3 times a week only.

Ammonia - havent tested
Nirite - havent tested
Nitrates - no idea 100? 160? can't tell lots of nitrates
PH - 5.7 when co2 is off under 5 when co2 is on 

Because of the low PH the two SAE I added has died.... 1 oto has also disappeared but that could just because it's an Oto from big als and they do that..I also have lots of newborn endler fries and a few small female endlers.

I remember tearing this tank down at least 3 times in the pass 5 years and changing the substrate from BDBS to eco complete. I recently tore down this tank and downgraded to a 20g long instead. In the process of that I took out all the eco completed and thoroughly rinsed it in a bucket with old tank water. That was done around Christmas day last year, I was hoping that would resolve my low PH problem but it has not, it did resolve my high Nitrate problem but it has slowly creeped up since than. My next step is to do %50 once a week and hopefully the water chemistry stabilizes closer to my tap water. PH is measured with API Ph tester (not expired), a cheapo yellow PH Pen, a better red PH pen, and a high quality PH pen. All the same results so for sure my Ph has crashed. For now I have stopped daily dosing fertlizers until I can get the nitrate and PH in check.


----------



## planter (Jun 9, 2008)

I'd strip the substrate and get new stuff. If you really want to save it or you could clean the hell out of it but new is better. Chances are the old stuff is depleted and so full of crap that's is messing with the water chemistry. 

After that with clean filters there should be no reason you can't reboot the tank. 5 years is a good run with a planted tank.


----------



## infolific (Apr 10, 2016)

If you want to experiment, I'd add some crushed coral to your filter or somewhere there is water flow. The crushed coral will dissolve in low pH and will cause the pH to rise. As the pH rises, the rate the coral dissolves will slow so eventually the pH should stabilize. The coral will continue to "battle" whatever is pushing the pH down and you may end up at a workable value.

The coral will also raise GH and TDS. I believe endlers are fine with higher GH and TDS.

Of course, you won't learn what's pushing the pH down, but at least you'll know something about crushed coral


----------



## mousey (Mar 28, 2011)

Just as aside I would be interested in what the nitrates were. 
I had a friend who never cleaned her tank. It had been set up for years. It had no live plants -just those artificial ornaments. I gave her some of my plants and they grew like crazy. I told her about the nitrate issues and she could care less but allowed me to bring my test kits for all substances . I was surprised that there was 0 ammonia, nitrite and nitrate. So her tank obviously did the nitrification cycle.
Did not get a chance to test ph but I am assuming it was ok as she had hundreds of guppies, mollies and swords in the tank at various stages of life.


----------



## infolific (Apr 10, 2016)

mousey said:


> I had a friend who never cleaned her tank. It had been set up for years. It had no live plants -just those artificial ornaments. I gave her some of my plants and they grew like crazy. I told her about the nitrate issues and she could care less but allowed me to bring my test kits for all substances . I was surprised that there was 0 ammonia, nitrite and nitrate.


When you say never cleaned her tank do you also mean she never changed the water? If she didn't, I don't see how there could then be 0 nitrates after years. No ammonia and no nitrites is believable with enough surfaces for the denitrification process to happen.

Did she have something out of the ordinary for filtratration? A deep substrate?


----------



## coldmantis (Apr 5, 2010)

I been doing a 5g water change on monday, wednesday, friday. Tested the PH and it's about 6.5 this is with the co2 on for at least 2 hours, Nitrates are 40. Hopefully 2 more weeks of 5g water change three times a week will reset it back to normal.


----------



## mousey (Mar 28, 2011)

cant remember how deep the substrate was but all they ever did was top up the evaporated water. It was a big tank - likely 75 gallons.


----------



## BillD (Jun 5, 2006)

coldmantis said:


> I been doing a 5g water change on monday, wednesday, friday. Tested the PH and it's about 6.5 this is with the co2 on for at least 2 hours, Nitrates are 40. Hopefully 2 more weeks of 5g water change three times a week will reset it back to normal.


You need to test the pH before there is CO2 injection, as it will lower the pH.


----------



## coldmantis (Apr 5, 2010)

yes I know I keep notes of the ph, of course I can only take proper notes on the weekend since I work 9-5. So If I'm home by 6pm and do a water change I can't measure the water at 5pm since thats when the co2 turns on. I measured yesterday (saturday) 6.25ph @ 4:20pm, 5.56ph @ 7:25pm and finally 5.3ph @ 12:50am. There is some improvement since a few weeks ago at the end of the co2 period it would be under 5ph.


----------



## df001 (Nov 13, 2007)

I'd be really curious to know what the carbonate hardness level is? IIRC part of old-tank symptom is the nitrite/nitrate cycle using up available carbonates causing the ph to drop. It would explain why your PH was so low with the co2 - no ability for the water to buffer.

anyone have any thoughts?


----------



## coldmantis (Apr 5, 2010)

df001 said:


> I'd be really curious to know what the carbonate hardness level is? IIRC part of old-tank symptom is the nitrite/nitrate cycle using up available carbonates causing the ph to drop. It would explain why your PH was so low with the co2 - no ability for the water to buffer.
> 
> anyone have any thoughts?


I rarely ever test KH on a non shrimp breeding tank, but since I stopped breeding Crystals this gives me an excuse to use the Kh tester. I'll do a test tonight and report back.


----------



## coldmantis (Apr 5, 2010)

Just tested the KH it is 2, damn pretty low. I think normally it's should be around the 7-9 mark.


----------



## planter (Jun 9, 2008)

Yeah that's low. Do you have anything in the tank that could effect your kh?


----------



## coldmantis (Apr 5, 2010)

planter said:


> Yeah that's low. Do you have anything in the tank that could effect your kh?


Hmm let me think

Terracotta pots from Dollarama
Black rubber bands from Dollarama

No Wood, Stones of any kind nada just Eco-complete and plants. I just tested my wife's goldfish tank which has the same Pots and black rubber bands KH is 5, PH is 7.7 on that tank.


----------



## df001 (Nov 13, 2007)

time to chuck some crushed coral or limestone chips into your filter, slowly buffering your KH back up, will help raise PH, provide carbonates needed for the nitrogen cycle bacteria, and hopefully get your tank squared away.


----------



## coldmantis (Apr 5, 2010)

df001 said:


> time to chuck some crushed coral or limestone chips into your filter.


I think I might have too, I have a calcium reactor with what I believe to be large crush corals. I might throw that in the next time I clean my eheim.


----------



## planter (Jun 9, 2008)

That's really weird....


----------



## coldmantis (Apr 5, 2010)

Ph is slowly looking good and Nirate is at a more comfortable level, hopefully it levels out by mid March.


----------

