Algaecide and super high Nitrates

[Craig Brown]

I've been struggling with green water since I filled my pond in the Spring. Took dozens of suggestions; installed UV; etc. Clarity improved to a more translucent green. With one month remaining of summer, I decided to try an Algaecide. I used
(the correct amount) of Microbe Lift Pond Algaway 5.4 ALGA32. I've got 3 water falls and put in 3 air stones (its about 1,800 gallons) to off set the low O2 level caused by Algaecides.

I did a water test. PH, Amonia and Nitrite are fine. Nitrate is crazy high, like the highest number on the chart. Can I assume it is the Algaecide that would cause this or should I add an emergency treatment? The fish are acting normal, Thanks!

 

[Meyer Jordan]

This is typically the result of using an algaecide. Algae, especially planktonic, will thrive on elevated levels of Nitrate (and often Phosphorus). 'Pea Soup' is the usual result of this population explosion. The application of an algaecide may kill the planktonic algae which will then be broken down by bacteria in turn releasing the Nitrate (and Phosphorus) back into the water column. Hence the high Nitrate reading that you obtained from your water test. In short order a new algae bloom may occur to feast on these now available nutrients.
Unless the nutrient level is reduced, you are fighting a losing battle. Add more plants to your pond. These will out compete the planktonic algae for the available nutrients resulting a lasting water clarity.
Nitrate is toxic to fish only at extremely high levels. Levels not usually encountered in a Garden pond.

 

[Craig Brown]

I've got a lot of plants. The above two small ponds are about 200 and 300 gallons. The surface is 100% covered by plants. Using bamboo, I keep the plants in the lower pond over to the side in order to leave a little area to see the fish ... if the water ever clears (the same water runs through all three ponds). This was my last-ditch effort to get some fish viewing time for the summer. Hopefully it will be better next summer. If not, I've still got some nice, healthy plants!

 

[Meyer Jordan]

Your planting seems to be predominantly Water Hyacinth. I would try a little more diversity.
Even so, with this many plants, you should not have a level of Nitrate sufficient to sustain an algae bloom. How much and often are you feeding your fish? Are you removing plant foliage as it dies? This excess Nitrate has to be originating someplace. Find the source and you have solved your problem.

 

[Craig Brown]

It could be the food. I put a hula hoop in when I feed to keep the food out of the skimmer. But the koi slap the hoop and food ends up in the skimmer. The plants are mostly Water Hyacinth and Water Lettuce. I had a few Mosaic plants which the Koi destroyed. Small plants like duckweed end up in the skimmer. What would you suggest?

 

[Mmathis]

How many fish do you have and how big?

 

[cas]

Wow. I can't grow water hyacinths that look that good for nothing. When I had a new pond and my yellow flag irises hadn't matured yet, I used submerged plants of anacharis and hornwort to control my green water. I used about 50 bundles for my 1,000 gallons.

 

[Meyer Jordan]

Are you adding extra food to offset that which goes into the skimmer? How much are you feeding and how often? Mmathis has already asked about the fish.
All you have are floating plants, no submerged or emergents. Plants from either or both of the latter categories will add diversity. Choose those that will thrive in your Horticultural zone.

 

[Craig Brown]

There are about 12 fish in the big pond. One is 20+ inches. Maybe 4 are 16 inches. The rest range from 12 to 6”.
Ammonia is zero. Nitrites are zero. PH is about 7.9.

I throw the food into the hoop a little at a time. I do this for the five minutes or until there are no fish eating.
I think the Nitrate level has to do with the chemical in the algaecide. I would bet that in two days it is a lot less. Still, I’ll keep an eye on the food.

The Hyacinths: I don’t know why, but they grow crazy fast and big. I had not intended to fill the small pond until next year, but the hyacinths totally covered all surface area (and I didn’t want to mulch them), so I filled it with water to hold the hyacinths. But only one had flowers.

 

[morewater]

I would suggest Sweet Flag as a marginal.

Tough root structure, nearly Koi-proof. Self-propagating, free-spreading, easily pruned.

Keep in mind that when you kill off algae using an algaecide, the "dead" algae doesn't just go "poof....magic", it sinks and then decomposes.

 

[Mucky_Waters]

your pond looks kind of foamy, do you have a skimmer?

 

[Craig Brown]

The foam came from the Algaecide, maybe dead algae. I have a big Easypro Skimmer to the right. In it is a 1/3 HP pump (overkill for the system). In regard to dead algae, I've got a bottom drain and algae ends up either in the skimmer or the waterfall filter. When the warterfall is full of algae, I empty it through a ball valve on the bottom. The good bacteria stay in the filters. The algaecide was a one shot deal. I had issues in the spring that lead to density of algae. The UV should keep it under control from here out. I don't mind green-tinted water, I just wanted to be sure there was still fish in there

 

[budgenator]

The foam came from the Algaecide, maybe dead algae. I have a big Easypro Skimmer to the right. In it is a 1/3 HP pump (overkill for the system).

I think the skimmer that @Mucky_Waters is talking about is a protein skimmer or foam fractionator like http://www.koi-bito.com/forum/main-forum/10649-son-phoam-phraxionator-created.html this one. It causes the dissolved organics to foam up and they are separated from the water. Any DOC (Dissolved Organic Compounds) that are separated from the water, don't have to be digested by your biological filter, giving it a chance to catch up with the load.

 

[mgmine]

A UV light will clear up anything. There is something wrong with the one you bought or the water is going through it too fast.

 

[keyplayer]

I've been struggling with green water since I filled my pond in the Spring. Took dozens of suggestions; installed UV; etc. Clarity improved to a more translucent green. With one month remaining of summer, I decided to try an Algaecide. I used
(the correct amount) of Microbe Lift Pond Algaway 5.4 ALGA32. I've got 3 water falls and put in 3 air stones (its about 1,800 gallons) to off set the low O2 level caused by Algaecides.

I did a water test. PH, Amonia and Nitrite are fine. Nitrate is crazy high, like the highest number on the chart. Can I assume it is the Algaecide that would cause this or should I add an emergency treatment? The fish are acting normal, Thanks!

FIRST THING is to ditch that expensive and USELESS UV device and stop dumping toxic chemicals into a pond which should, if the natural balance is correctly planned and effected, be all you need. After 6 years of crystal clear water in a highly overpopulated pond and in a climate hostile to water plants I can testify to the ONLY thing you need: a GOOD biological filter system preferably one you build yourself at low cost and high efficiency. Mine is hugely overbuilt but it cost very little and has been 110% successful! And, BTW, more plants is always better — the few I can successfully grow provide natural uptake of nitrates and other products of decomposition, shelter from predators for the fish, frogs and other denizens, and look good to boot!