[Just40Fun]

A friend has a 125g fish only tank that he keeps mainly cichlids. His nitrate level has always been high in 80-100ppm range and gh/kg both in the 180-200ppm range. After he saw my planted tank, he also planted some a-swords and java ferns to enhance the looks and to reduce nitrate. He has 1.5w/g of lighting, no CO2 and wc every 2-3 weeks.

His swords and java ferns are doing very poorly, yellow leaves wilting away. His nitrate is still in the 80-100 range.

Could it be that the phosphate level is too low so the plants can't use the nitrate in the water? or the water too hard? what would be the right advice for him?

 

[mrbelvedere]

He has 200 watts over his tank with epic nutrient levels? How are his algae levels? Then again, cichlids love to munch on algae.....

What he needs are floating plants. Java fern isn't doing anything to reduce nitrate. It will only absorb a very small amount of nitrate in a given time. I suggest things like duckweed, watersprite, and frogbit.

I'm sure with all those fish he has plenty of phosphate.

Water isn't too hard, Amazon swords can grow in a bed of pure calcium carbonate.

He also needs to do much larger and many more water changes (weekly or biweekly), and perhaps add Purigen. This coupled with the floating plants should give him excellent water quality.

 

[eklikewhoa]

Does he have Nitrates in his tap water?

I agree with MrBelvedere, there is no substitute for water changes.

 

[Just40Fun]

Thanks guys, I am not sure floating plants will work since his tank has overflow. Just asked him to check the nitrate level of tap water, which measured 20ppm, so the high level were due to high fish level etc.,

 

[eklikewhoa]

If he is starting with 20ppms of Nitrate in the tap then he doesn't have a good start.

 

[mrbelvedere]

True, denitrate (product by Seachem) could help. However, nitrates in the 30-40 ppm range are perfectly safe for fish, and with planting could be reduced. Get on those water changes.

Maybe he could perhaps put floaters in his sump, with a really strong light for growth. That might work, or screen his overflow over to allow floaters.

 

[Just40Fun]

Interestingly, he has high nitrate, no algae issue, but his plants are wilting also.

 

[Wasserpest]

Besides nitrates and phosphates, plants need some potassium and micros. If leaves turn yellow, iron/manganese could be deficient. Adding some micro mix like Flourish might improve things.

Swords like some nutrients around their roots, if they are planted in regularly cleaned gravel they could suffer.

 

[unirdna]

Swords like some nutrients around their roots, if they are planted in regularly cleaned gravel they could suffer.

This was my thought. I had a long history (before I learned 'bout all this PT stuff) of swords doing marvelous for about a month, then turning yellow and croaking off. Those roots need chow.

 

[Just40Fun]

I doubt the gravel gets cleaned often with such infrequent wc. With his fish load, one could assume the gravel are full of fish pooh in various stage of decomposing.

 

[Just40Fun]

Could this be why? Crushed coral were mixed in with pea gravel as substrate ... ie the sword plants were planted in crushed corals.

 

[TAF CAF]

I think something that may be missing in this conversation is 'SALT???'

Everyone I know around here that has cichlids adds a good deal of salts to their water... might this be the case?

 

[Just40Fun]

I think something that may be missing in this conversation is 'SALT???'

Everyone I know around here that has cichlids adds a good deal of salts to their water... might this be the case?

good point, let me find out.

 

[Just40Fun]

went to visit friend and took a look at his tank. well, the swords have almost completely wilted away, no more leaves just a few brown stems. I have just suggested to put fert tabs near the roots, which he will do this weekend after a water change.

I think those swords plants may still be able to be revived although their leaves and most stems have wilted away. Anyone happened to know how long would it take before any new leaves start growing?

 

[TAF CAF]

Any word on the salt issue?

 

[Just40Fun]

Any word on the salt issue?

Sorry, forgot to post. I did ask about salt. He said he doesn't normally add salt of anykind. Except almost a year ago he used salt to cure ick. But multiple wc has occured since. The water in our city is very hard off the tap so we don't really need to add buffer.

 

[EdTheEdge]

xxxxxxx
CO2

 

[Just40Fun]

CO2 definitely will help. On the other hand, this guy's tank is basically a low light low tech affair. A-swords could grow in a low tech environment too, so I think there are other factors involved that are killing his plants.

 

[confuted]

You don't need CO2 to grow swords. It's possible that he got emersed grown plants, and the emersed growth is dying and the submerged growth hasn't started yet.

 

[Just40Fun]

You don't need CO2 to grow swords. It's possible that he got emersed grown plants, and the emersed growth is dying and the submerged growth hasn't started yet.

I read that emersed growth died quickly once submerged. In his case, it took months for the swords to wilt and died. So the mystery continues. So far what we know:

1. He has low light: 1.5w/g 10,000k lights
2. His tank has heavy fish load.
3. The Nitrate read 80-100ppm and phosphate should be high due to fish load. Water hard, GH and KH in 150-300 range.
4. He only do water change once in 2-3 weeks.
5. His doesn't fert this plants until this week, he put plant tab under the roots.
6. He has gravel + crushed coral as substrate.
7. No CO2.
8. His swords disappeared (died?) after wilting for months.

LOL, so what is killing the plants? Lack of Potassium? lack of trace? no enough light? need CO2?