Pond Boss Forums INTRO Questions & Observations Do I need fertilizer?

How do I know if I need fertilizer? Before the rain and tornadoes, the water clarity was about arm's deep. Of course, now it is zero. I am also concerned that with the amount of water that flows through the pond, any fertilizer I put in will just wash downstream.

Yes, it will wash away. Until the water stops flowing, there's nothing you can do.

If your clarity was good before the deluge, it should return when the non organics settle to the bottom.

You can improve water fertility even with water flow through. How much flow through do you have on a normal basis ?

Eric, how? I get the idea that the flow through is something new. Give me a hand here.

The flow varies greatly, but almost never completely stops. My WAG is between 100 - 400 gpm normally, depending on rain. I get this number from the amount of water in the pond, 19 million gallons, and the fact that it took 3 weeks to fill with only one decent rain.

I understand that I don't want too much clarity, I figured that arm's depth clarity was about right. This all came up because my neighbor thinks we should fertilize, and I'm not sure we need it, or that we would just be spinning our wheels by trying.

The flow through concept is not new. All things work in degrees. Fertilizing is not an all or nothing idea or benefit. You don't have to have 12in visibilities to be helping. There can be a big increase and it may not be visible to your eye.

Think about it this way. In a pond in its natural condition it may have plankton at a rate of X per meter squared (pms) and you may not be able to see it as green water (clear with 6 ft visibility). You can add enough fertilizer to make it green with 12 in. visibility and that may be equal to 1000 X pms. You can instead add a lot less fertility and have plankton @ 200 X pms. The first event 1000 X pms may be ideal and result in a 4 fold increase in pond productivity. But the second event - plankton @ 200 X pms is also a big improvement and may raise productivity 1.5 fold.

The same can be said for time. The ideal may be 12 in visa. all spring and summer with a 4 fold production increase. But 30 in visa for 2.5 mths resulting in a 75% plankton increase is a lot better than 6 ft all spring and summer.

So if by adding some fertilizer you get a plankton increase of a decent % for a fair time period you are much better off.

If the pond looses water by flow through at a rate of total pond vol replacement from spring through summer of 100% (that is a lot) you can still increase its productivity for a given period of time. This is even more so (and easier to achieve) if your water discharge is from several feet down (5 ft)as in many pond water control systems. Ours loses water from 5 ft below the surface and thus the good fertile water is only replaced if the water goes over the top of the big stand pipe ( a major 8in rain event). Our flow through comes from 5 ft down through the diagonal pipe. We have flow through most of the summer and 90% of the rest of the year through a 6 in pipe and have no problem establishing a visible bloom. A lot less than visible is still a big improvement.

Jersey I would say it is worth a try if you have good alkalinity (25 ppm +). Two bags of pro-sol (50lbs total) when the water is stabilized at 65 F or above (about May 1 your location) in 10 acres will cost about $ 75. Go slow - add half - wait a week and see results - then add the rest in 2 applications a week apart - wait and watch and measure visibility with a disc. But first you have to decide if the need exists which is an entirely different question of how many fish at what sizes and how many will be removed.

The diagonal pipe on the water side of the large pipes releases water from 5 feet below full pool. The white pipe on one is an added siphon irrelevant to this discussion.

Wow. Thanks ewest, I may have to read this a couple of times.
My siphons are about 7 feet deep, so that sounds good based on what you say. The issue I still can't grasp is that I am replacing all of the water in the pond every two to four weeks, depending on rain. Remember, the pond is actualy part of the stream.

Engineering would be fun if it weren't for all the technical stuff.

Jersey not sure you remember we discussed this. You have a large watershed. I told you normally I would not rec. However since you have a siphon you have a big advantage. The reason is your pulling the same amount of water but not the nutrients nor the phytoplanktn right off the surface. Also we now have clients not start until June this is when our rains slow dramatically. Like Ewest said it is an increase even though you only get the increase part of the growing season. BTW you do realize I have 16 tons of this fertilizer sitting around, so love to get you some.

Greg,
Get in touch with me before you bring the catfish. I'd like to discuss further.
Thanks.