Plant only filtration (why not popular in the hobby???)

[wrslrcichlid]

They are red eared sliders, and you are probably right. I am going to build a shelf planter (something similar to ithurtz's one) made of egg crate for my 125g african cichlid tank first. I will see how sturdy that is and then decide how to make it for the turtles. It will probably be best to use a plastic window planter, the only problem is that we don't keep the water completely full so the turtles can bathe without being able to climb out of the tank. So basically I will have to find a way to lower the planter into the tank - I wonder if it would float and then I just have figure a way to keep it upright. We'll see I guess, but cichlid tank first.

 

[JK47]

Not entirely true or false. DOC's are generally addressed in nature by a complete ecosystem. In an aquaponics setup items other than those not used for plant life don't generally get to a point where they need to be addressed by water changes. This is not to say water changes might not sometimes be warranted, however they can also be detrimental depending on the setup or usage you have. In a setup inside the home where bio-loads may not be fully addressed by plant and or bio filters regular water changes may be quite appropriate. In a full fledged aquaponics system the plants require the "food" load and thus the system is "loaded" to address the plants needs. A healthy system requires a balanced load... plants however can compensate for a low load or deficient load. A system I am currently assisting with has been running non stop for 5 years without a water change, water is only added.. the plants and fish are all extremely healthy and have both been used as food for the entire life cycle of the system. The hardest part is when the plants or fish are harvested, at that point balance is hard to maintain.

So, like i was saying, in home systems where this balance is harder to maintain due to bio load or plant filtration it may be quite advisable to do water changes. Since most of the readers of this thread are focused on ornamental style plants you advice may be even more valid. If however people are going to teh more extreme measure of say a full on aquaponics system the info provided here is only the tip of the iceberg.

I agree with you 100%. I'll be blunt and honest though and say that I do not want members reading this assuming they can drop a pothos vine in an HOB filter and not do water changes anymore, it's not that simple or even practical. That is more what my post was gear driven towards. In a full aquiponics system it is very possible to not have to do water changes. I have done it myself with results I am pleased with. I know the actual plant load it would take to manage a system like this on a larger scale (say tanks 125g+) and it is a significant plant load. To the point that it becomes ugly to look at to say the least (for most members) I myself love how it looks.

Now for a little update of my own. My drip system (24/7 continuous water change) changes 134% of the water in my 125 gallon per week. I still can pick up a small measurable amount of nitrate (5ppm - 10ppm at most, depending on my feeeding and when I test). My 10 gallon with no drip, only plants has never given me a reading and has been running for a year... The stock list different as are a lot of other variables obviously but none the less still long term ongoing results. My 120 gallon, now that's a different story...

 

[wrslrcichlid]

Well, it has been a week since I threw the pothos into my 125g african cichlid tank. My last water change was 2/11, so it has been a full 10 days. When I put the pothos in on 2/15 my nitrates were about 10ppm, which is pretty standard 4-5 days after a water change (normally I would have done a water change on that day). I have been paying attention all week, but today my nitrates were 10-20ppm!!! I knew plants helped, but I wasn't expecting that. If I normally waited 10 days my nitrates would be upwards of 40ppm. I know my tank isn't as full as some fill their tanks, but it's a 125g with 30-35 fish.

Haven't gotten a change to build my shelf planter but hope to this coming weekend. I am also still trying to find arrowhead plants, so if anyone has any ideas where I could fine some that would be great.

I am going to post some pics shortly.

 

[wrslrcichlid]

The first pothos I bought. It was tiny.

Washing it to remove all fertilizers and stuff

The small pothos ended up being a bunch of smaller pieces - not just one plant. Somewhat frustrating.

My nitrate test from 2/15

Just the small plant in the tank on 2/15

Nitrate test today (2/22) Not much different!!!

What the plants look like today (2/22)

 

[wrslrcichlid]

Please excuse the apple headphones tied loosely around the plants with the book light. Just keep the plants from sinking and from floating all over the tank. Didn't have any string - so I DIY!!

 

[wrslrcichlid]

Oh and I should add that I did a good water change today, 30-40%. I am curious, if I end up adding enough plants to keep nitrates low what is the maximum time span that I could put between water changes? I know there are other reasons, besides just the accumulation of nitrates, that make water changes necessary - just wondering how lazy I could get? Probably won't go that far, but maybe.

 

[ITHURTZ]

You could get the ultimate lazy, at that point you just replace the evaporated water. Thats all I do on the 55. And DAM did your pothos grow.

Arrowheads are easy to find, atleast where I am at in Lake county. Home depot, lowes should still have plants. Super walmart still has plants usually in the garden center. I got my last 3 plants from there $2.75-$3 for 3" potted ones couple weeks ago.

 

[JamesF]

Just replacing evaporated water is a rather cruel torture for your fish. The plants only remove certain items. Mainly nitrogen, phos and potassium. All the fish hormones will remain in the water. Many of these hormones exist for the sole purpose of stunting fish in dense populations.
Every tank I have get nitrogen added regularly through the week. ALL of my plants have a constant nitrate reading of 0. They all still get a 50% water change every two weeks. Why? To remove the stuff we can't test for.
If your whole purpose in keeping aquariums is to avoid water changes, take up a hobby more suited to you. Become a couch potato.

 

[wrslrcichlid]

JamesF, I don't know if you are responding to me or to ithurtz, but as I said I am not trying to stop water changes all together. I may go that route in the future with a vermaponics system, but am simply asking how long I COULD go between water changes if I add enough plants to keep nitrates at or near 0. You mentioned you do a WC every 2 weeks, would that be your suggestion or do you think you could go longer without negatively affecting fish? Thanks.

 

[JamesF]

Doing away with waterchanges has been mentioned several times in this thread. It's a part of the hobby. Live with it.
I do every two weeks because I have large carnivorous fish that are still growing and I want them to reach their maximum potential. Good food and clean water are the best ways to do this. If I didn't have three kids and tons of activities on the weekends and evenings I'd be doing the water changes every week.
I'm not saying that adding plants can't reduce the amount of water changes, but it will never do away with them. Plants just don't remove everything.