Newbie question about silt cleaning options

[Gavin Adcock]

I'm new to the site and new to pond ownership - please be gentle!

I built a pond last spring (2016) in an unused garden feature (large raised flowerbed behind a granite bench). It's about 7m long and a little over 1m wide (roughly rectangular). There are 3 shelves of differing depths with an average depth of 50cm and the deepest point is about 80cm. So, roughly 3000 litres in total. It is fed by rain water runnoff from the house roof, although in periods of dry, hot weather, this needs to be topped up with tap water (very clean, non-chlorinated Swiss water!). We put 5 or 6 goldfish in the first year, and within weeks they had reproduced - my guess is we now have about 30 goldfish. The fish survived the harsh swiss winter. They were recently joined by a frog/toad.

My initial plan was to have a totally natural pond with no artificial aids (oxygen or pump). After the fish reproduced, I was concerned for their wellfare so added a cheap solar powered oxygenator. This lasted one season. Around the time it broke - this spring - the water had turned green with algea and my research told me I probably need a filter/UV setup. The first solution was a Heissner filter (HLF6000) which initially cleaned up the algae well, but the algae came back with the hot summer weather. I realised the pump was probably under-rated for the fish stock I have, so upgraded then to a Heissner FPU7000. Both pumps ran for a few weeks, the water turned crystal clear, and for a few weeks now I've just been running the FPU7000.

In the very hot weather we've been having, water temp is now 26°C. Researching pond equilibrium made me realise I needed more plant life, so have added to last years plants and I would guess the water surface is 30-40% covered. All this is just background...

Now I have pristine clear water as you'd expect in the Swiss mountains. This lets me see the floor of the pond and I realise it is being covered with a thick layer of very fine silt. I think I should be tackling this before it becomes too deep, but I'm not certain if I should clean it, and how. Research into simple solutions (manual suction pumps, etc) seems to indicate that the products in the market aren't reliable unless you send $$$ for a decent electric pump/vacuum - which seems overkill in my situation.

So, to my questions:
1. Should I be managing the silt?
2. If so, what products or solutions come well recommended?

If I've left out important info., or if photos would help, please let me know!

Cheers, Gavin.

 

[MoonShadows]

Afraid I can't help you on this topic, but there are plenty of friendly knowledgeable folks with a lot of experience who are always willing to help. I'm sure some will give you advice when they see your post. Posting pictures may be of help, too...besides we always love to see them!

 

[Gavin Adcock]

Some photos, by popular demand.

As you can see, the pond is partly covered (about 2m in length) by a wooden terrace which joins to the house. This is the deepest part of the pond so rarely froze over last winter (the shallow end was permanently frozen).

 

[sissy]

welcome and really nice pond but goldfish produce way to many babies .What do you plan on for winter .

 

[Lisak1]

Welcome to the GPF! What a pretty pond and beautiful setting!

When you say "thick layer" how think would you guess it to be?

 

[Gavin Adcock]

Thanks for the replies.

Winter plans? I have none. If this is about concern for the fish, they survived last winter with minimal (next to none) feeding.

The silt layer is maybe 1cm thick but it seems to have started this summer as temperatures warmed up. So, I'm wondering what I need to do as a general silt management approach.

It is extremely fine, brown is colour. When dislodged it gets into suspension in the water and then slowly resettles. Before I started the filter I did use a "sludge buster" product (Envii Sludge Clear) but, as the water was opaque, it was hard to tell what effect, if any, this had. I had also hoped that the filter would circulate the water enough to suck up any silt, but that isn't happening.

 

[DutchMuch]

get a tube and slowly siphon it out of the bottom of the pond? takes time but it is guarantee'd to work.

 

[sissy]

I just use a fine swimming pool net and put my crate in my waterfall area with quilt batting in it and pump hose pumping water from the pond into the quilt batting .The stuff that I don't get with the net will get caught in the quilt batting

 

[Gavin Adcock]

Thanks, DutchMuch. Do you mean take a simple plastic tube and siphon the 'dirtiest' water manually? Or are there recommended siphon products available?

 

[sissy]

my set up I keep this in my waterfall all the time .I did a splitter off my pump

 

[DutchMuch]

Thanks, DutchMuch. Do you mean take a simple plastic tube and siphon the 'dirtiest' water manually? Or are there recommended siphon products available?

If you have spare tubing like flexible tubing, no holes, then put one end in the water, and put your mouth on the other end and suck really quick, and then remove your mouth from it, you've created a siphon if the water is coming out now. Make sure the tube is long enough for you to maneuver it along the floor of your pond so you can get the silt sucked out.

Here are some products: http://www.pythonproducts.com/
This one is a HIGHLY recommended brand.

 

[Gavin Adcock]

On closer inspection today it would seem I have the beginnings of a string algae issue... the silt appeared to be "growing" into the water and running my hand through this, it leaves a stringy, green mass on my fingers. A closer look around the pond shows me this is appearing mainly in the shallow end and especially around the plants.

Any help or advice?

My one immediate idea is to drop the second filter back in at the shallow end to both clean it and get the water circulating better through the whole pond.

 

[DutchMuch]

String algae loves water circulation, in my experience.
As to how to get rid of it, idk how to do that in a pond. Let others chime in

 

[Lisak1]

Any help or advice?

Algae is a symptom - not a problem. Some algae is normal and desirable. Too much is an indication of too many nutrients in the water, which means either: too few plants, too many fish, or too much food. All of those are controllable - address those things and your pond will naturally come into a balance where you don't have "too much" of anything. Don't start chasing solutions - you'll throw lots of money at a problem that will resolve itself with proper pond management.

 

[Lisak1]

String algae loves water circulation, in my experience.

We've noted that, too, in our pond - the only string algae we get anymore (if we get any at all) is on the waterfall.